Illuminating Those Who Lurk in the Shadows
An Examination of the Use of Psychological Profiling in Identifying Violent Criminals in the Modern Age

Abstract

This study examines the role of psychological profiling in apprehending violent criminals. Psychological profiling involves analyzing behavioral patterns at crime scenes, exploring the relationships between victims, and identifying characteristics and tendencies of offenders. It is currently used by many law enforcement agencies across the country to narrow down a pool of potential suspects and direct researchers, making the most of the limited manpower available. There is, however, a significant limitation in the literature and available evidence that suggests its tenets may be based on intuition and anecdotal evidence purported by investigators, subject to internal bias and thus should not be considered an empirically validated science or discipline. As such, some studies have found that the cognitive bias of the profilers themselves may have hindered 24.5% of the investigations involved (Trager & Brewster, 2001). This thesis examines the history and application of psychological profiling in the modern era using the work of theorists: Plato, Freud, Nietzsche, Schopenhauer, Kant, Samenow, and Von Helmholtz. Then applying the work of these theorists using the acts committed by Hitler, The Boston Strangler, The Unabomber, Bundy, Son of Sam, BTK and The Zodiac. Findings suggest that criminal profiling is a valuable tool amongst the many that help solve what appear to be unreasonable acts of violence. Recommendations from this thesis can inform both the academic and professional communities about its utility and value in identifying and apprehending violent criminals in contemporary society.

Acknowledgements

I want to thank my thesis chair, Dr. Stephen Holmes, for his guidance and support through this entire thesis process. His mentorship, patience, and encouragement pushed me to think more critically and grow academically. I am truly grateful for the time and effort he invested in helping me shape this project into something I am extremely proud of.

I would also like to sincerely thank my committee members, Dr. Mark Winton, Dr. Nicholas Paul, Dr. Shamir Ratansi, and HUT liaison Dr. Sherron Killingsworth Roberts for their thoughtful feedback, insight, and support throughout this journey. Their perspective challenged me to strengthen my research, and I deeply appreciate the role they played in the completion of this thesis.

In addition, I want to express my gratitude to The Burnett Honors College at the University of Central Florida for providing me with the opportunities, resources, and environment that allowed me to succeed. The support from faculty and staff has made a lasting impact on my academic experience.

Most importantly, I want to thank my mom and dad. None of this would have been possible without them. Their hard work and sacrifices made it possible for me to become the first in my family to attend college. Their dedication, love, and belief in me have carried me through every challenge. I hope this accomplishment reflects the strength and commitment they have shown my entire life, because I would not be here without them.

Introduction

Serial killers captivate the American imagination at every turn, from bestselling truecrime novels to late-night movie marathons. But why do these killers continuously repeat the cycle? What drives them to commit these crimes? And what is the best method to catch them? “The FBI defines criminal profiling as a technique used to identify a perpetrator of a violent crime by identifying the personality and behavioral characteristics of the offender based upon an analysis of the crime committed.” (Burgess, 1986, p. 9). Over the past two decades, the creation of series like Criminal Minds and Mindhunter has increased awareness of the usefulness of this criminal assessment tool. These popular shows often portray criminal profiling as an almost infallible investigative technique; however, the reality is far more complex and, at times, controversial.

Although criminal profiling is an investigative tool, it is not a definitive solution, and it does not guarantee success. Throughout its history, criminal profiling has been used both successfully and unsuccessfully. The Boston Strangler case is an excellent example of a time when profiling failed to provide definitive proof of a single suspect. Whereas the Unabomber case allowed profilers to provide structured insight into seemingly irrational acts of violence, aiding both the investigation and understanding of the offender.

Statement of the Problem

Despite its portrayal in the media and its growing use in law enforcement, criminal profiling remains a widely debated, controversial, and misunderstood investigative technique. There is ongoing debate over the scientific validity of profiling, consistency across cases, and overall impact on the speed or accuracy of apprehending serial offenders. While high-profile cases like those of Ted Kaczynski and Dennis Rader illustrate both its potential and its limitations, there is limited empirical research connecting specific psychological motivators, such as the need for control, sexual or power gratification, and ritualized compulsion, with successful outcomes, without a clearer understanding of how these psychological factors translate into successful investigative leads, profiling risks being dismissed as guesswork rather than a helpful tool grounded in behavioral science (Kocis & Hayes, 2004; Petherick & Brooks, 2020).

This work examines the history and utility of psychological profiling from the early twentieth century up to the present day. This thesis examines the myths surrounding this practice and its current application. This analysis utilizes a multidisciplinary approach, drawing on research from various disciplines to provide the academic and practitioner communities with a realistic sense of its utility across different crime types. Ultimately, it is hoped that this comprehensive review of its application will generate future research ideas and inform criminal justice and investigative policy and practice.

Literature Review

To understand psychological profiling and its application to real-world crime, it is essential to examine its history, past uses, and current applications. To examine its history, one must first look back at the writings of America’s great crime novelists, such as Edgar Allen Poe. In his short story “Murders in the Rue Morgue” (1840), Poe wrote about a detective by the name of C. August Dupin. Dupin was a fictional character who understood basic human behavior and used his intellect to help solve crimes. As an academic and university-trained professional, Dupin set the standard for later crime novelists, including Sir Arthur Conan Doyle, when he began his series of books featuring another fictional detective, Sherlock Holmes.

However, it was not until 1888 that the first real case emerged, where an outside consultant was brought in to assist law enforcement in solving a crime by developing a psychological profile of an unknown offender. This individual was a gentleman named Thomas Bond. Bond was an English surgeon who assisted the police investigating the murder of Mary Ann (Polly) Nichols in the Whitechapel district in London, England. In his analysis, Bond examined autopsy notes and crime scene evidence to make assumptions about the motive and psychological characteristics of the killer that would later become known as the “Ripper.” Although his profile was relatively crude by today's standards, he described the killer’s age, demeanor, and appearance. Specifically, he described the killer as a “respectfully dressed middle-aged man with both solitary and eccentric habits” (MacDonald, 2024). Further, he wrote that the killer was likely not employed in a traditional manner and had little or no scientific or anatomical training. Even though the identity of Jack the Ripper remains a mystery today, and Bond’s profile did not lead to an arrest or conviction, it is noted as the first of its kind and set the stage for the field of behavioral analysis.

Origins of Our Understanding of Crime and Criminal Responsibility

Historically, the roots of psychological profiling date back well before the late 19th century. The origins of behavioral analysis (e.g., psychological profiling) go back to ancient Greece. One of the earliest thinkers to deeply consider criminal human behavior and justice was Plato, the classical Greek philosopher. Plato examined the roots of justice and wrongdoing in both The Republic (Plato, 1968) and Laws (Plato, 2004). In The Republic, Plato described the human soul as composed of three parts, reason, spirit, and appetite, arguing that justice results from the proper balance among them (Plato, 1968). This mirrors modern psychological insights, in which crimes may arise from an imbalance, such as when impulse overrides rational thought. In Laws (2004), Plato moved beyond abstract theory and addressed moral and criminal responsibility, asserting that not all crimes stem from the same root. He distinguished between those committed out of ignorance and those born of illness, suggesting different punishments and corrective approaches depending on the offender’s motivations (Pangle, 2009). This view laid philosophical groundwork for what would later become criminal profiling. Though Plato lived centuries before the foundations of modern psychological thought and forensic science, his insights into human motivation and moral agency remain relevant to guiding behavioral analysis today.

Freud, Nietzsche, and Hidden Motivations for Criminal Acts and Deeds

When the foundation for profiling was laid, the field of psychology was in its infancy. Sigmund Freud, the founder of modern-day psychology, was not even born. However, his ideas were present and circulating in the academic community. In fact, many were already attempting to understand violent and deviant human behavior. The lesser-known psychologist Friedrich Nietzsche wrote about his theory of “will power.” Specifically, Nietzsche (1968) believed that there was a hidden motivation or power behind every human behavior. In essence, what he was describing in Freudian terms is the inner workings of the id and the role of the subconscious.

Although psychological profiling was in its primitive form, it was not until Sigmund Freud’s work in the late 19th and early 20th centuries that the scientific study of the human mind and subconscious motivations truly began to take shape. Freud (1923) introduced groundbreaking theories about the structure of the mind, particularly the concepts of the id, ego, and superego, as well as the importance of unconscious and early childhood experiences. Freud's focus on unconscious drives, repression, and internal conflict helped establish a framework for understanding the motives and behaviors of criminal offenders, influencing future methods in criminal profiling (McLeod, 2024).

To understand Freud’s theories, you must understand the person, his background, and his career. Early in his professional life, he was appointed lecturer on nervous diseases at the University of Vienna. This role marked the beginning of his formal academic career and gave him the platform to develop and share his early theories on the human mind. “After spending time in Paris and attending lectures given by French neurologist Jean-Martin Charcot, Freud became more interested in theories explaining the human mind” (Cherry, 2022). Charcot’s work with hypnosis and hysteria had a profound impact on Freud, sparking his interest in psychological causes of mental illness rather than traditional biological ones. His experience in Paris helped lay the groundwork for what would become psychoanalysis, and his work ultimately influenced how psychologists and criminal profilers understand unconscious motivation and deviant behavior (Phillips, 2014).

Freud’s pioneering professional works laid out the groundwork for modern psychological thought and, of course, psychological profiling. It is now widely accepted that many disturbed individuals may act out unconscious desires or impulses, sometimes manifesting themselves as criminal acts. Freud believed that much of human behavior is driven by repressed emotions, unresolved childhood experiences, and instinctual urges that operate beneath the surface of our conscious mind (McLeod, 2024). He believed that early trauma, such as abuse, neglect, or exposure to violence, can profoundly affect a person’s psychological development. Further supporting this perspective, a 2021 study published in Alpha Psychiatry examined 313 male prisoners and found a strong correlation between childhood trauma and violent criminal behavior. The results showed that childhood trauma scores significantly predicted violent tendencies in later adulthood (Cantürk, Faraji, & Tezcan, 2021). Thus, those who have experienced abuse as a child may often develop a distorted sense of control, attachment issues, a skewed sense of self-worth, and a distorted view of the world. In criminal profiling, understanding an offender’s background, especially histories of trauma, can reveal unconscious motivations that influence behavior. The idea is that by identifying early or childhood psychological wounds that may have gone unaddressed, profilers can develop a deeper understanding not only of what an offender did, but also of the potential factors that contributed to why they did it.

The Balance Between Human Will, Instinctual Drives, and BASE Rationality

Other early theorists have examined criminality and unconscious drives differently. For instance, Arthur Schopenhauer, a 19th-century German philosopher, played a significant role in shaping early thought around human motivation and behavior. Schopenhauer’s work distinguishes the will (a blind, driving force within individuals) and our conscious perception of the world (Schopenhauer, 1966). This framework was then applied not only to metaphysics but also to social institutions such as justice and law. According to one analysis, Schopenhauer believed legal systems should mediate between individual wills and impulsive drives by appealing to reason and representation. (Angeles, Baptista, Tucci, 2021). Schopenhauer’s emphasis on the hidden, irrational “will” laid the groundwork for viewing criminals as subjects influenced by deep inner forces, rather than merely moral agents acting rationally.

Similarly, Immanuel Kant, a German philosopher and a central thinker of the Enlightenment, took a distinct approach to the study of human desires, drives, and actions. Unlike Freud or Schopenhauer, who emphasized unconscious and irrational drives, Kant believed that human beings are rational agents capable of acting according to moral law. “Kant’s theory of justice has two main goals: (1) providing an account of civic freedom, and (2) describing the ideal roles of virtuous citizens within a political community” (Steffen, 2019, p. 32). In this sense, Kant did not view justice as simply the enforcement of laws, but as the structure through which individuals coexist and hold one another accountable through shared moral principles.

In the context of profiling or understanding criminal behavior, Kant’s ideas offer contrast to theories that attribute crime to unconscious forces. Instead, Kant’s philosophy suggests that individuals can choose right from wrong. While modern behavioral analysis often focuses on psychological or environmental factors, Kant reminds readers of the enduring question of moral accountability and human choice. However, today, there are some questions as to whether many violent criminals are capable of rational thought. Researchers such as Stanton Samenow (2022), who have studied psychopaths and sociopaths extensively, have found that many of our most violent criminals see the world and react differently to it than the rest of the population.

Unconscious Inference and Von Helmholtz’s Influence

Other theorists have taken a different approach to examining the criminal mind and its motivations. For instance, Hermann von Helmholtz, a German physician and physicist, introduced the influential concept of unconscious inference, which “implies that human vision is incomplete and that the unconscious mind infers details to create a complete picture” (“Unconscious Inference”). Helmholtz’s (1925) theory helps explain how individuals, including offenders and investigators, may make rapid, unconscious judgments about situations, motives, or people. These inferences, often outside conscious awareness, can affect behavior, decisionmaking, and the interpretation of social cues. What this means is that many individuals make decisions and engage in potentially criminal acts without truly understanding why they did them or what triggered the acute acts of violence.

Many in the social sciences conflate Freud's work and theory of unconscious drives with von Helmholtz’s work on unconscious inference. Both appear to be hidden from the participant's view, but they are conceptually distinct. Von Helmholtz explains that perception (and therefore reality) is grounded in experience and physiology, whereas Freud believed that unconscious drives motivate behavior. What this means is that, under von Helmholtz's theory, the mechanisms used in criminal behavior are learned to some degree by being placed in the conscious mind (although they may represent an incomplete interpretation of an act or event). In contrast, Freud’s theory is innate and unconscious. This is a key distinction because when examining and attempting to understand violent criminal behavior, the theory of unconscious inference would argue that monsters are made. In contrast, Freud would state that monsters are born.

Putting Classical Theories to Work

Just what makes people behave the way they do is something that we have strived to understand for over a millennium. Whether our actions and deeds stem from unconscious motivations or our own perceptions may never be known with certainty, as it often depends on the individual. But what is known is that criminal motivations to do horrible things to our friends and neighbors can stem from anywhere. They may even include a lack of impulse control and abnormalities in the brain stem, specifically in the areas that process emotions (Simpson & Balsam, 2016; Siever, 2008).

At the same time, behaviorist theorists like B. F. Skinner (Frietze, 2019) and, to some degree, von Helmholtz (1925) emphasized environmental reinforcement, suggesting that motivation can also be shaped by social context and learned responses. Ultimately, the intersection of internal psychological processes, past experiences, neurobiology, and environmental influences contributes to a complex portrait of human motivation.

Regardless of the source, these ideas about what makes criminals act the way they do and prey on other human beings took shape in the late 1800s and early 1900s to the extent that theorists and forensic scientists began to hypothesize about what caused individuals to commit the crimes they did and how to not only understand their behavior but stop it. One of the first modern examples of how psychological profiling was used in the modern age was its use by the Office of Strategic Services (OSS) in 1942 to study the acts and proclivities of Adolf Hitler. However, for many, the development of the Behavioral Science Unit at the Federal Bureau of Investigation marked the point at which much of the seminal work in profiling began to come together. The founding of this unit is covered in the next section.

The Development of the Behavioral Science Unit at the FBI and the Origins of Modern Criminal Profiling

The FBI’s Behavioral Science Unit (BSU), founded in 1972, played a pivotal role in the development of modern criminal profiling (FBI, n.d.). Created to study the behavior of violent offenders, the BSU was led by pioneering agents like John E. Douglas, Robert Ressler, and Roy Hazelwood, who interviewed notorious criminals such as Ted Bundy and Ed Kemper to “understand motives and to create a centralized database of serial offenders in the nation.” (CriminalJusticePrograms.com, n.d.). Their work led to the creation of offender typologies, such as organized versus disorganized killers, and the development of criminal personality profiles based on crime scene analysis. The BSU’s methods were instrumental in solving highprofile cases like the Atlanta Child Murders and helped solidify profiling as a legitimate investigative tool.

One of the most notable serial killers that helped shape the unit as the profession knows it today is John Wayne Gacy. Gacy, known as the “Killer Clown,” killed 33 young men and boys in the 1970s, burying many of them beneath his home in Illinois. Although the unit did not directly profile Gacy, the interviews conducted after his apprehension were critical to “reinforcing what Ressler believed about organized killers” (Grimmick, 2019). Gacy was socially skilled, maintained employment, and planned his crimes in a way that made him undetectable for years; traits that align closely with what the FBI defines as an organized killer.

Over time, the BSU evolved into the Behavioral Analysis Unit (BAU), which continues to support complex investigations (FBI, n.d.). While profiling is not without criticism, some argue it can be overly subjective or unreliable. The unit laid the foundation for behavioral analysis, which continues to develop alongside advancements in psychology, data science, and forensic technology.

The Use and Utility of Modern-day Criminal Profiling

It is crucial to understand the core psychological motivators of serial offenders, such as the need for control, sexual or power gratification, and ritualized compulsions. Although criminal profiling is often criticized for its potential biases and subjectivity, a profile translates these behavioral patterns into investigative leads, significantly accelerating the identification and apprehension of serial offenders.

A comprehensive meta-analysis by Fox and Farrington (2018) examined over forty years of research on offender profiling to evaluate its effectiveness as an investigative tool. Their findings show that while profiling has contributed to a better understanding of offender behavior and victim patterns, its actual success in identifying offenders remains limited. Most profiles were found to be descriptive rather than predictive, offering general personality insights instead of actionable leads. Fox and Farrington (2018) also pointed out that a lot of profiling research lacks rigorous testing or consistent methods, meaning it often relies more on experience than on science. Their work supports Brooks and Petherick's (2020) argument that profiling needs to become more structured and evidence-based to truly help investigations.

Today, criminal profiling remains a valuable, although imperfect, tool within the broader context of investigative work. While it still faces criticism regarding its scientific rigor and occasional inaccuracy, decades of refinement through the Behavioral Analysis Unit and other structured ongoing academic research have transformed profiling from a speculative technique into a structured process informed by psychology, criminology, and data analysis (Brooks & Petherick, 2020). As technology advances and more empirical research emerges, modern profiling continues to evolve, shifting from intuition-driven guesses to behaviorally grounded assessments that, when used in conjunction with forensic evidence and investigative strategy, can significantly impact the solution of violent crimes.

Recently, increased attention has been paid to new research stemming from lessons learned not only from profiling errors and oversights but also from interviews with serial offenders who are often convicted and serving time. This research, generally conducted in psychology and psychiatry, indicates that some offenders simply do not behave or even think like everyone else. And it is the reliance on rational thought and action, which may limit our ability to explain criminally vile humans. One such theoretical paradigm is referred to as “lone wolf theory.”

The Lone Wolf Theory

The Lone Wolf Theory (Hamm, 2013) refers to someone who acts alone, without direct ties to a larger group. Serial offenders, more often than not, act as lone wolves, adding to the nightmare of catching them. Operating independently does not allow traditional investigative strategies to flourish, hindering the investigation. This is where criminal profiling comes into play. A profile can help investigators define behavioral patterns, psychological traits, and possible motivations that can link what seems unrelated to crimes. Lone wolves often leave subtle clues in their methods of operation, victim selection, or crime-scene behavior, and these consistencies can be crucial in narrowing suspects. However, while profiling can be a powerful tool, it is not without its challenges. Lone wolves are often unpredictable and may defy established patterns, so profiles must be used carefully alongside other investigative methods. (Bakker & Graaf, 2010).

Stanton Samenow’s Thoughts on Pyychopaths and Sociopaths

Stanton Samenow is a clinical psychologist, expert in criminal behavior, and author of Inside the Criminal Mind (2022). In his studies, Samenow interviewed scores of psychopaths and sociopaths and developed his own theory of just who these violent criminals are. He does not believe that many typical criminogenic explanations for why these criminals behave as they do are accurate. Focusing on their general thought patterns, Samenow claims that criminals are just different than most people. They think differently. They are not held to the same moral or ethical constraints that shape most people’s behavior. Instead, criminals process environmental stimuli often to their own advantage, not thinking about the long-term repercussions of their decision, similar to a psychopath or sociopath. A psychopath is generally thought to be someone who has a shallow emotional response, exhibits exaggerated impulsivity, lacks empathy, and often suffers a predisposition to engage in antisocial behavior (Ditzell & Haghighi, 2021). A sociopath is someone with a form of personality disorder, affecting how a person thinks, feels, and behaves (Ditzell & Haghighi, 2021).

In his analysis, Samenow attempts to avoid using the labels of psychopaths or sociopaths. Instead, he focuses on the criminal mindset itself, arguing that behavior stems from distorted thinking patterns, or what he calls errors in thinking, and personal choices rather than medical or social conditions. Overall, Samenow’s main assertion is that criminals suffer from thinking errors rather than an illness that warrants a clinical or medical diagnosis. Regardless of the label, he notes that criminals tend to display patterns of entitlement, power hunger, lying, pride, and victim stance. These patterns drive their actions; all aimed at achieving their personal goals.

Samenow’s work reshaped profiling by moving it away from labeling criminals as psychopaths or sociopaths and toward understanding how they think. His ideas encourage profilers to study the cognitive patterns and personal choices behind violent acts, helping make behavioral analysis more grounded and responsible.

The next section will focus on the methods used in this analysis and the historical profiles developed to assess not only the accuracy of behavioral analysis and the technique, but also their utility for law enforcement as tools to narrow down a list of suspects.

Methods

This analysis employs the collective case study method as the primary research framework for examining the profiles of seven well-known, violent serial offenders. This methodological approach, rooted in qualitative inquiry, facilitates an in-depth examination of complex behavioral patterns by allowing for the systematic collection, organization, and interpretation of detailed accounts of each offender’s life history, criminal activity, and psychological attributes.

The case method’s capacity to contextualize individual actions within broader environmental, socio-cultural, and psychological dimensions enables a nuanced understanding of the multifactorial origins of serial violent behavior. By engaging with each case as a discrete unit of analysis, the study preserves the integrity of the individual offender’s crimes while simultaneously enabling cross-comparisons applying practices that reveal underlying patterns and distinctions.

The method and comparison of demographic backgrounds, developmental histories, crime-scene behaviors, and victim-selection strategies facilitate the identification of recurrent themes and unique features that may inform both theoretical models and practical investigative approaches. It is hoped that this research will contribute to a deeper understanding of the nature of violent serial offending. In doing so, the analysis will not only deepen our scholarly understanding of such offenders but also provide direction for investigators and the profession on tools for profiling, prevention, and investigative practices.

Criteria for Inclusion

Each profile was chosen based on a specific set of criteria.

• First, the individuals under study must be violent criminals whose crimes resulted in the death of intended victims.

• Second, the profile itself must be publicly available so that each can be viewed and assessed by others.

• Third, the crime (or crimes) must have occurred in the past so that an assessment of the integrity and fidelity of the proposed characteristics of the offender can be identified.

• Fourth, the offender must meet the clinical characteristics necessary to be coded as either a psychopath or sociopath, consistent with Samenow’s framework.

• Fifth, the offender must be male (or proposed to be male), since the field recognizes that males and females often not only think differently but also act out their crimes in different ways (Zimmer, 2021).

The case study methodology is suitable for this topic, because it allows for a detailed examination of the profiling process from start to finish. By focusing on high-profile cases, analyses of high-profile criminals can perhaps offer lessons on the successes and failures of profiling in real-world applications, considering rare or noteworthy events and eliminating subjective interpretations, confirmation bias, and a lack of rigorous empirical validation.

The process and methodology will enable this thesis to discuss, confirm, and dispel common myths about profiling, such as its portrayal as a nearly infallible science that easily reveals offenders' identities or predicts their actions with high accuracy. Thus, by delving deep into seven individual cases, additional hypotheses and patterns may be generated and tested. The cases below, organized by findings, are discussed in chronological order to highlight the evolution of profiling and its successes and failures.

The Profile of Adolf Hitler and Lessons Learned

During World War II, the OSS commissioned psychoanalyst Walter Langer to produce a psychological assessment of Adolf Hitler. In his report, A Psychological Analysis of Adolf Hitler: His Life and Legend (1943), Langer combined available intelligence, historical records, and psychoanalytic theory to predict Hitler’s behavior and possible outcomes. Although he never met Hitler, Langer analyzed second-hand accounts, writings, and observed patterns to build his profile. Among his predictions, Langer argues that Hitler would likely commit suicide if faced with inevitable defeat, an outcome that ultimately proved accurate. He also described Hitler as a paranoid, narcissistic, and rigid thinker, suggesting that these traits would guide both his military strategy and his eventual downfall.

This assessment was among the first times psychology was formally applied to national security. It demonstrated the potential of behavioral analysis to predict threats and understand dangerous individuals, laying out the groundwork for forensic psychology and, later, behavioral profiling used by the FBI and other law enforcement agencies. Langer’s work also foreshadowed later profiling methods, such as the case study approach and the analysis of writing or communications, which became especially significant in modern investigations, such as the Unabomber case. More broadly, his assessment legitimized the role of psychology in intelligence and criminal investigation, showing that even without direct access to a subject, it was possible to construct a meaningful and actionable psychological profile of an individual who was responsible for the deaths of 45 million people during his twelve-year reign (O’Reilly & Hammer, 2025).

The Profile of the Boston Strangler and Lessons Learned

From 1962 to 1964, 11 women in the Boston area were murdered. The Boston Strangler case stumped experts for 50 years, until DNA evidence finally linked Albert DeSalvo to at least one of the victims in this infamous case. During the years of the murders, the citizens of Boston were paralyzed with fear. Newspapers ran daily headlines about the killings, and women across the city began changing their routines, locking their doors, and living in constant anxiety. Under immense public and political pressure, investigators turned to psychiatrists and psychologists in hopes that a psychological profile might provide the breakthrough they needed.

The profile that emerged suggested there were two killers. Experts described them as lonely men who lived alone, likely worked as schoolteachers, and that one of them was probably homosexual. At the time, such claims reflected the field’s reliance on stereotypes about deviance and sexuality rather than on empirical evidence. When Albert DeSalvo was eventually arrested for a series of sexual assaults and later linked to the murders, the reality was scarily different. DeSalvo was neither a teacher nor homosexual. He was a married father who worked in construction. Almost every major point of the original profile was incorrect (Baker, 1985).

This failure exposed several problems with early profiling. It revealed the danger of leaning on cultural assumptions about who “looked like” a killer rather than building conclusions from data and evidence. It also shows how misleading a faulty profile can be, as it may lead investigators away from the true offender and delay justice for the victims. This issue also helps explain why profiling was mostly dismissed in its infancy and regarded as just guesswork.

The inaccuracy in the Boston Strangler profile highlighted the need for more research and reinforced the importance of pairing behavioral insights with forensic and investigative work. Later efforts by the FBI’s Behavioral Science Unit would move in this direction, as their interviews with serial killers and the development of offender typologies allowed profiling to move past guesswork. In this way, the missteps of the Boston Strangler case contributed, although indirectly, to the reinforcement of profiling as an investigative tool.

The Profile of the Unabomber and Lessons Learned

Profiling often helps make sense of violent acts and supports investigations. In the case of the Unabomber, Ted Kaczynski, the attacks appeared ideologically driven and random, targeting universities, airlines, and technology experts over nearly two decades. The randomness of the attacks made it difficult to impose a rational framework for effective profiling. Traditional investigative methods yielded few leads, prompting agents to rely heavily on behavioral profiling to understand Kaczynski’s motives and identity.

Unlike the speculative, stereotype-driven approach to the Boston Strangler case, the FBI’s Behavioral Science Unit employed a more systematic analysis. Profilers examined the bomber’s choices of targets, methods of construction, and eventually his writings, including the infamous 35,000-word manifesto, Industrial Society and Its Future. They concluded that the offender was likely a highly intelligent, white male, socially isolated, with strong antitechnology and anti-government views. While still broad, this profile was far more grounded in observable behavior and linguistic evidence than earlier attempts at profiling (FBI, n.d.).

Kaczynski also painted a perfect picture of a lone wolf offender. This aspect made it especially difficult for law enforcement to track him. As stated earlier, tracking lone wolf offenders is incredibly difficult, as they leave few social connections for investigators to trace, leaving their behavior and writings as the only clues available (Bakker & Graaf, 2010). In Kaczynski’s case, his isolation in a remote Montana cabin and his rejection of modern society reinforced his ability to operate undetected for nearly two decades.

Investigators finally had a breakthrough when Kaczynski’s manifesto was published in major newspapers, leading his brother to recognize his writing style and alert authorities (FBI, n.d.). The case demonstrated the power of combining behavioral analysis with forensic linguistics, as the study of his word choices and sentence patterns became central in identifying him. In this way, the Unabomber investigation highlighted how profiling could move beyond speculation to serve as a practical, collaborative tool, showing its maturation from the downfall of the Boston Strangler case.

The Profile of Ted Bundy and Lessons Learned

Ted Bundy’s case is central to the development of modern profiling because his ability to appear ordinary while committing extraordinary acts of violence forced investigators and psychologists to expand their frameworks. To the non-informed layperson, Bundy lived a respectable life, with education, political connections, and social charm, while secretly engaging in a series of brutal murders across multiple states (Plercy, n.d.; OJP/NCJRS, n.d.). This duality challenged stereotypes of killers as visibly deviant and highlighted the need for more nuanced profiling methods.

The FBI’s Behavioral Science Unit began developing these methods in the 1970s. In the Bundy case, analysts noted his preference for young women with long hair parted in the middle, his reliance on social spaces like universities and beaches to meet victims, and his use of charm and ruses to lure them (Federal Bureau of Investigation, 2013). These observations helped show how a killer’s behavior, choice of victims, and crime scene patterns could be used to predict future actions, even when the suspect appeared completely normal.

Psychologists also tried to understand Bundy’s personality. Research has described him as a psychopath, but many experts argue that labels do not fully explain him. Bundy was manipulative and self-centered, but he was also confident and socially skilled, which made him more dangerous (Plercy, n.d.). This case highlighted that personality disorders can overlap, and that not every serial killer fits neatly into one category (Plercy, n.d.).

Bundy’s writings reveal how much he valued control and image. Surviving prison letters were consistently neat, carefully organized, and free from emotional chaos. The orderliness of these documents reflects the same discipline and control visible in his crimes. Criminologist Amelie Pedneault (n.d.) shows how Bundy, in interviews, often framed his victims as “images” or “objects,” which helped him emotionally distance himself from what he had done. She explained that he used techniques like denying responsibility and minimizing his victims’ suffering, showing how he rationalized his actions (Pedneault, n.d.). This control over how he presented himself made it even harder to understand him truly.

Overall, Bundy's case illustrates both the potential and the limits of profiling. His crimes helped solidify behavioral analysis as a key investigative tool with the FBI (FBI, 2013). At the same time, his ability to craft controlled narratives, whether through his letters or outward charm, demonstrated how easily a calculating offender can fool even experts. For this reason, Bundy remains a pivotal figure in the history of behavioral profiling, forcing the discipline to become more detailed, evidence-based, and aware of the psychological complexity of offenders.

The Profile of Son of Sam and Lessons Learned

David Berkowitz, also known as Son of Sam, terrorized the young women and couples of New York City. From 1976 to 1977, Berkowitz killed six people and wounded seven others using a .44 caliber revolver. His crimes, letters to the press, and his eventual arrest contributed significantly to the development of behavioral profiling in the United States.

According to Themis (2014), the term “serial murderer” was coined by FBI Special Agent Robert Ressler in response to the Son of Sam case. During this period, law enforcement began to recognize patterns in offenders who committed multiple killings over a period of time. This idea reshaped investigative strategies within the FBI’s Behavioral Science Unit. Themis (2015) points out that while figures like Jack the Ripper, Ted Bundy, and the Zodiac Killer are often viewed as “typical” serial killers, middle-aged white males with various personality disorders, Berkowitz’s case stood out because of his unpredictable behavior and seemingly random choice of victims.

Berkowitz’s background also reflects many of the psychological challenges often associated with serial offenders. Adopted by Nathan and Pearl Berkowitz, he reportedly showed signs of depression, isolation, and erratic behavior from a young age. After serving in the U.S. Army, he returned to New York, where he began his series of shootings and sending taunting letters to the police and media under the name “Son of Sam.” In those letters, he sometimes claimed that demonic voices ordered him to kill (Lindsey, 2024). On August 10, 1977, Berkowitz was arrested after investigators tied a parking ticket to his vehicle near a crime scene, and he quickly confessed to the attacks. He was sentenced to 365 years in prison (Lindsey, 2024). His criminal case led to the establishment of “Son of Sam” laws, designed to prevent criminals from profiting from the media attention generated by their crimes.

Moreover, the APA’s Speaking of Psychology: Inside the Mind of a Serial Killer podcast highlights how the Berkowitz case, among others, encouraged deeper research into the psychology and neuroscience behind serial murder. The podcast explores how researchers seek to understand brain function, personality traits, and environmental influences that may increase the likelihood of violent behavior (APA, n.d.). Looking at Berkowitz through the psychological lens helps explain him not just as a criminal, but as an important case for understanding how and why serial killers think the way they do.

The Profile of Btk and Lessons Learned

Dennis Rader, known as the Bind, Torture, Kill (BTK) killer, terrorized Wichita, Kansas, for decades. Between 1974 and 1991, he murdered ten people, often sending taunting letters and poems to police and the media to boast about his crimes (Sullivan, 2021). What made BTK particularly disturbing was the double life he lived. Rader was a husband, father, church council president, and compliance officer who appeared to live an average suburban life. His ability to maintain this facade while committing brutal murders challenged many of the assumption's profilers held about the behavioral patterns of serial killers (Sullivan, 2021).

The FBI’s Behavioral Science Unit considered the BTK case a rare opportunity for profiling because Rader openly communicated with authorities. Profilers had access to his letters, phone recordings, and detailed crime scene evidence that seemed to offer insight into his psyche (Jackson, 2014). Two FBI teams worked to build a psychological profile, but despite the abundance of evidence, their results were inconsistent and contradictory. One profile suggested BTK was a married man in his 30s with children, while another described him as a single, socially isolated lone wolf. These mixed depictions only added to the confusion in the investigation (Lynes & Wilson, 2014). Consistent with Brooks and Petherick’s (2020) observation, the BTK investigation demonstrates how unstructured profiling contributed to conflicting interpretations.

Rader’s obsession with control and his carefully planned crimes showed traits of an organized offender, yet the FBI struggled to use this information to find him (Crime & Justice, 2016). Forensic psychiatrists later criticized this approach, arguing that the FBI relied too much on guesswork rather than actual solid evidence (UC Davis, 2005). Rader's letters clearly revealed narcissism and a desire for attention, but profiling failed to identify him because it focused too much on broad personality types instead of specific clues.

Ultimately, BTK was caught in 2005, not through profiling but through forensic technology. Rader sent a floppy disk to the police, believing it was untraceable. Investigators were able to recover metadata linking the disk to Christ Lutheran Church, where Rader volunteered, thereby directly connecting him to the crimes. This mistake led to his arrest and confession (Sullivan, 2021). The BTK case highlights both the appeal and the limitations of profiling; it can help investigators understand an offender's mind, but it rarely solves the case alone. Profiling gave law enforcement a framework for understanding BTK’s motives and personality, but it was digital forensics that brought his decades-long killing spree to an end (Crime and Justice, 2016; Jackson, 2014; UC Davis, 2005).

The Profile of the Zodiac Killer and Lessons Learned

Between December 1968 and October 1969, the San Francisco Bay area was terrorized by an unknown serial killer known as the Zodiac. The Zodiac Killer murdered several victims and taunted both the police and the public through cryptic letters and ciphers (FBI, 2007). His crimes, targeting couples and using different weapons, created a case that blurred the line between homicide and psychological warfare (McCrary, n.d.; Konrad, n.d.). Unlike Bundy, who was charming, Zodiac was a distant, faceless predator who hid behind cryptic messages and symbols, turning him into a psychological jigsaw puzzle (Konrad, n.d.).

Profilers found the Zodiac case especially difficult because his methods lacked consistency, he shifted from shooting to stabbing, and targeted victims with no clear pattern (McCrary, n.d). The FBI’s involvement was largely supportive, limited to forensic and handwriting analysis due to overlapping jurisdictions, which made it difficult to build a cohesive behavioral profile (FBI, 2007). Zodiac is a prime example of an outlier in the profiling community. His ability to manipulate not only law enforcement but the media without leaving significant forensic evidence made him one of the hardest killers to track. A narcissistic predator, Zodiac is thought to have a mix of antisocial personality disorder, schizotypal traits, and sadistic tendencies. It is thought that the Zodiac derived gratification not only from murder, but from the control he exerted through fear and communication (Konrad, n.d.).

Despite this case going unsolved for decades, profiling has done little to narrow down the list of suspects. The Zodiac’s unpredictability defied the standard organized/disorganized framework, and his taunting letters encouraged overinterpretation by profilers (Konrad, n.d.). Handwriting and fingerprint comparisons yielded no match, showing that behavioral insights alone were insufficient for identification (FBI, 2007; McCrary, n.d.).

This case remains one of the most studied cases in American history, not because of the number of victims, but because of the psychological complexity the killer displayed (Konrad, n.d.). His manipulation redefined how investigators understood criminal communication, while his enduring anonymity underscored the limits of behavioral profiling and the growing need for forensic science (McCrary, n.d.; FBI, 2007).

The Zodiac investigation revealed both limitations and the importance of profiling. Traditional methods struggled to capture, but behavioral analysis was able to recognize the killer’s craving for recognition and control, which allowed insights that guided communication with the public and prevented further panic. This case ultimately pushed the field toward more flexible and evidence-based techniques, securing its place as a valuable tool in modern law enforcement (FBI, 2007; Konrad, n.d.).

Analysis

The following analysis will examine each of the seven profiles, evaluating how each was developed, the accuracy of its conclusions, and the lessons learned from it. By assessing both the strengths and limitations of these profiles, it is easy to see how behavioral analysis has evolved. From these conclusions, it will become evident how offenders' assumptions have helped improve investigations and how some have led them astray.

Analysis of Adolf Hitler

Adolf Hitler was analyzed by Walter Langer in 1943, officially becoming the first profile applied to national security. Langer’s work laid the groundwork for the future of behavioral analysis and helped shape what it is today. His assessment, commissioned by the Office of Strategic Services (OSS), aimed to predict Hitler’s behavior as Germany neared defeat using secondhand interviews, historical research, and psychoanalytic theory. Relying heavily on the words of those who knew him and on Freud's psychological concepts, Langer's profile accurately defined several key traits: narcissism, paranoia, and obsession. However, the analysis also included major inaccuracies. Langer’s ideas were influenced by Freudian psychology, which led to some over-the-top and unfounded claims about Hitler’s personality and behavior. Additionally, the lack of empirical data and his reliance on secondhand accounts weakened the profile’s reliability. Based on current knowledge, the profile could be improved by incorporating real behavioral evidence and input from different fields rather than relying solely on theory. Today, profiling focuses more on data and research, which helps make profiles more accurate and less based on personal interpretation (Erb, 2025).

Analysis of the Boston Strangler

The Boston Strangler case in the early 1960s became one of the most famous examples of criminal profiling in American history. Desperate for leads, investigators turned to psychiatrists and psychologists for help. The experts based their assessment on limited crimescene information and early psychological theories rather than on concrete evidence. The profile they created reflected the social attitudes and stereotypes of the time more than behavioral data. While the profilers correctly identified that the killer targeted vulnerable women and gained their trust before attacking, almost every other aspect of the analysis was inaccurate. The Strangler’s profile could have been improved by grounding it in concrete forensic evidence, victimology, and behavioral patterns rather than personal assumptions. Modern profiling methods would use data-driven analysis and cross-disciplinary input to produce more accurate and reliable assessments (Walden University, n.d.).

Analysis of Ted Kaczynski

Ted Kaczynski, the Unabomber, carried out ideologically driven, random attacks against airlines, universities, and technology experts. The Behavioral Analysis Unit developed the profile by studying the bomb construction, the victims’ backgrounds, and the language used in the letters sent to the media. The profile created relied heavily on occupational stereotypes, which was part of why it lacked key elements. To improve the profile, profilers could have spent more time on forensic technologies such as DNA and digital forensics. Today, profilers integrate behavioral and digital evidence to create more precise and unbiased assessments, an approach that might have identified Kaczynski earlier (Bellara, 2025).

Analysis of Ted Bundy

The Ted Bundy profile was formulated during the 1970s as investigators across multiple states struggled to connect a string of murders involving young women. The Bundy case was central to modern profiling development as observations helped show how a killer’s behavior can help predict future actions. Investigators initially struggled because Bundy’s outward normalcy and social skills did not fit the typical offender. The profile also failed to account for his mobility across state lines, which led to complications in the investigation. Communication among jurisdictions, victimology databases, and geographic profiling techniques could have been used to improve the profile's integrity. Another aspect that could have propelled the profile forward was information about Bundy’s childhood. It was evident that Bundy had a poor relationship with his mother, which led to resentment and feelings of humiliation (Piccotti & Kettler, 2023). Modern techniques also place more of an emphasis on understanding how offenders mask their violent tendencies behind social charm; an insight into the Bundy case helped establish future investigations.

Analysis of Son of Sam

Son of Sam, David Berkowitz, terrorized young women and couples from 1976 to 1977 in New York City. Investigators and profilers examined crime scene evidence, victimology, and the taunting letters sent to the police and media to form a psychological portrait of the killer. The profile described the offender as a white male in his mid-twenties to thirties, socially isolated, possibly a multiple killer, and paranoid. This investigation was complicated by the intense media coverage, which shaped public perception and sometimes influenced the profile's direction. To further improve this profile, the focus could shift to behavioral consistency and linguistic analysis of the letters, rather than speculation about multiple offenders. Modern profiling would also account for the impact of media pressure on both the investigation and the offender’s behavior, leading to a more balanced and evidence-based approach (Fernandez & Subtil, 2024).

Analysis of Dennis Rader

The Bind, Torture, Kill (BTK) terrorized Wichita, Kansas, between 1974 and 1991. Murdering ten people, Dennis Rader lived a disturbing double life as a husband, father, churchgoer, and secret serial killer. The profile was largely accurate, identifying his need for control and obsession with bondage and ritual. However, investigators were misled by conflicting profiles. Improving this profile could be done by recognizing organized offender characteristics and how they often maintain normal public identities while living out violent fantasies in secret. Today's profiling would also use digital forensics and communication analysis to track behavioral patterns in his letters and communications, methods that ultimately played a key role in the identification of Raider decades later (Slonoaps, 2024).

Analysis of the Zodiac

The Zodiac, known as a psychological jigsaw puzzle, taunted the San Francisco Bay area from 1968 to 1969. Targeting couples, using different weapons for each murder, and sending tormenting letters and ciphers to both the police and public. The opposite of Bundy in every way, Zodiac was and remains faceless and distant. The analysis of Zodiac relied heavily on speculation, as there was little forensic evidence, and the killer’s identity was never confirmed. Early profilers overestimated how organized and methodical the offender was, assuming a higher level of sophistication than what the evidence consistently supported. To better understand, the Zodiac profilers could have incorporated linguistic analysis alongside geographic profiling to more accurately identify his crime pattern and communications (Goodspeed, n.d.). Today, profiling integrates forensic linguistics and data-driven analysis, which are likely to yield a more accurate understanding of his motives and behavior, reducing the guesswork that characterized the early stages of the investigation.

Conclusion

Overall, these seven profiles illustrate how criminal profiling has evolved from a mix of psychological speculation and limited data into a more structured, evidence-based practice. Early profiles, like those of Hitler and the Boston Strangler, relied heavily on theory and assumption, while later cases, such as Bundy, BTK, and the Unabomber, show how the integration of behavioral science, forensic evidence, and technology improved accuracy. Each success and mistake contributed to refining the process, demonstrating the effectiveness of profiling when combined with other well-established investigative tools. The lessons learned from each case continue to shape modern behavioral analysis and ensure that profiling remains a valuable yet cautious tool in criminal investigations.

The evolution of criminal profiling is a fascinating timeline. Its roots can be traced all the way back to Plato and his ideas in The Laws and The Republic, and today it has become a mainstream concept popularized by TV shows and the media. The seven profiles highlighted in this paper are crucial for demonstrating the evolution of profiling and its importance as a tool that helps investigators better understand offenders.

Throughout its history, profiling has evolved from theory-based, speculative approaches to evidence-driven, data-supported methods. There are obvious failures and successes, but each played an important role in shaping modern practices. The failure of the BTK case taught profilers to delve deeper into the linguistic analysis of the clues/letters left by killers. Linguistic analysis examines the language used by an offender to gain insights into background information (e.g., education, culture) and to understand psychological traits better (Verbolabs, 2023). One can see the lesson learned in the Unabomber case, where the analysis of Kaczynski's 35,000-word manifesto ultimately led to his arrest.

Profiling is by no means a foolproof or purely scientific method; it must work alongside forensic and investigative tools to foster a successful investigation. Many of the failures seen throughout the history of profiling stem from investigators’ sole reliance on it. It is important to note that profiling will be forever evolving, learning from the mistakes of the past and advancing as technology, psychology, and data analytics do as well, to make a better, more structured future. The future and stability of profiling depends on balancing science, ethics, and critical thinking to help investigators narrow their offender pool and better understand the minds behind serious crimes.

References