Working in silence, motives unknown, the Unabomber eluded capture for nearly two decades.

His mail bombs killed three people and injured 23 others. The FBI had few clues to work with: fragments of metal and wood, shreds of paper, a sketch of a hooded man in sunglasses. But then the Unabomber became verbal, mailing a 35,000-word "manifesto" to two major newspapers, along with a series of chatty letters. In so doing he gave the FBI a far better idea of who they were dealing with. Last week the massive manhunt converged on a cabin in Montana, where the FBI found what it believes is the solution to the mystery: Theodore John Kaczynski.

The Unabomber case still is rife with uncertainties. But interviews with hundreds of people, including relatives, neighbors and colleagues, have uncovered new details of Kaczynski's life: his genius-level IQ, a social alienation so great he had to ask neighbors what day it was, his obsession with details, his reinvention as a mountain man who used a bucket for a toilet. The infamous manifesto can now be read not merely as an anti-technology diatribe but also as an autobiography, a psychological road map, providing the best explanation for why a brilliant young mathematician would throw away his career to become a hermit in remote Montana, hunting wild game, reading books by candlelight, tinkering with bombs.

"The system HAS TO force people to behave in ways that are increasingly remote from the natural pattern of human behavior. For example, the system needs scientists, mathematicians and engineers. It can't function without them. So heavy pressure is put on children to excel in these fields. It isn't natural for an adolescent human being to spend the bulk of his time sitting at a desk absorbed in study." -- the manifesto, paragraph 115

Kaczynski's jail cell has a toilet, a sink, a bed. In some ways it is an upgrade from his previous residence, the 10-by-12-foot wooden cabin on Humbug Contour Road, a dirt road winding up Bald Mountain on the western slope of the Continental Divide. The cabin, still sealed by the FBI, has no toilet, no plumbing, no water well, no sewage, no telephone, no electricity.

He hunted squirrels, rabbits and porcupines. He'd skin them and barbecue them in a fire pit outside his cabin.

"A young man goes through the power process by becoming a hunter, hunting not for sport or for fulfillment but to get meat that is necessary for food." -- the manifesto, paragraph 75

The FBI had anticipated that the Unabomber would turn out to be a professor denied tenure, or a graduate student unable to attain a doctorate. Kaczynski was no failure. He soared in his field. He won his doctorate and a prize at the University of Michigan for writing the best thesis. He was on a tenure track at Berkeley, steadily publishing papers. One day in 1969 (the day Richard M. Nixon took office, it so happens), Kaczynski announced his resignation in a two-line note to his department chairman. He later said he was leaving the field of mathematics, and didn't know what he wanted to do.

In fact, he left American society.

Kaczynski's cabin was lined with books. He had them special-ordered by the local library, some of them in foreign languages. And he had two manual typewriters. Authorities believe one of them is the typewriter that tapped out the manifesto, titled "Industrial Society and Its Future," the authorship listed as "FC," which authorities believe stands for "Freedom Club."

The Unabomber sent the manifesto to The Washington Post and the New York Times last year and threatened to mail another lethal bomb if one of the papers didn't publish it. After consultation with the FBI and the Justice Department, the two organizations jointly published the text in a supplement to The Post.

The Unabomber included with his text a diagram, with terms like "Frustration" and "Anxiety" and "Low self-esteem" radiating from a central problem: "Tendency to depression." No one recalls Kaczynski as seeming depressed, but he was strikingly alienated, a child who rarely played with other children, a college student who wouldn't eat with his housemates, a professor who wouldn't go for beer and pizza with colleagues. He was a misfit, literally: He and society didn't mesh. When the full story emerges it may become apparent that "FC" was an identity created by a man who struggled to understand his own social isolation, who made his weakness a virtue, and transformed his personality flaws into an elaborate philosophy justifying acts of long-distance terror.

One thing is certain, says Michael A. Rustigan, a criminologist at San Francisco State University who has studied the Unabomber case for more than a decade: There has never been a serial killer in the United States with Kaczynski's academic credentials. What's perplexing is that, as details emerge about Kaczynski, there's no obvious precipitating event to turn him into a killer.

"His murderous career is diametrically opposed to his background," says Rustigan.

So the story of Kaczynski remains for now incomplete, his biography full of gaps and uncertainties. Perhaps that also fits nicely with the Unabomber profile. Unabombers aren't social creatures. One would expect the author of the manifesto to be shadowy, isolated, a brooding and implacable force on the fringe of society. Kaczynski was very good at being a hermit. If Kaczynski is the Unabomber, then his mountain-man existence was both a philosophical statement and a great strategy for eluding capture.

Even when he was part of society, Kaczynski was largely silent, an enigma to those around him. In hundreds of interviews done by The Post in recent days, there is one salient fact: Hardly anyone seems to have really known him.

"Pathologically shy" is the description of one colleague. Other adjectives: "Withdrawn." "Quiet." "Earnest." "Reclusive."

No one remembers him smiling. No one remembers him laughing.

And as far as anyone can remember, Ted Kaczynski never had a friend.

His family called him "Teddy John." His brilliance emerged early. One day his father's best friend, a child psychologist named Ralph Meister, decided to give 6-year-old Teddy John a Stanford-Binet IQ test. Result: An IQ somewhere between 160 and 170, Meister estimated.

"Teddy John was the only kid I ever heard of who requested a copy of, and read, Robert's Rules of Order,' " Meister, now retired, told a reporter yesterday.

Teddy John would hole up in his room. Sometimes he went to the attic. He studied constantly. His uncle, Benny Dombek, thought such behavior "very strange." Teddy John didn't seem to have any girl friends or pals, his uncle said.

The Kaczynskis lived in the working-class Chicago suburb of Evergreen Park. His father, Theodore R. Kaczynski, known as "Turk," worked in a sausage factory on Chicago's South Side. He and his wife, Wanda, were well-read, politically liberal people of modest means. They had a second son, David, seven years Teddy John's junior, and much less withdrawn. It was David who eventually tied his own brother to the Unabomber's writings several months ago and reluctantly turned him in to the FBI.

When Teddy John reached the age of 12 he and a junior high school classmate, Dale Eickelman, occasionally played with homemade explosives. "We would go out to an open field, and I remember Ted had the know-how of putting together things like batteries, wire leads, potassium nitrate and whatever, and creating explosions," Eickelman, an anthropology professor at Dartmouth College, told the Daily Southtown newspaper in Chicago.

"We would just blow up weeds, nothing more," he said.

Ted looked normal enough in youth, even rather handsome. In high school he had the standard greased-back Elvis pompadour. He played trombone in the marching band. He was in the math club, the coin club, the biology club and the German club.

He stood out for his mind. He skipped two grades. In 1958 he was one of Evergreen Park High School's five National Merit Scholarship finalists.

"He went through high school like a shot," recalls classmate Donald Sobbe.

He made it to Harvard at 16, where he had the chance to socialize with the future leaders of America. He didn't. He lived among them, at Eliot House, one of Harvard's residences for undergraduates, but not really with them. Patrick S. McIntosh, 55, an astronomer in Boulder, Colo., who lived in Eliot House, said Kaczynski "avoided socialization to an extreme." He recalls that Kaczynski would come back from classes and virtually run down the hall to his room and slam the door closed.

His housemates remember that he had an annoying habit of rocking in a chair such that it banged against the wall. He was rocking and reading, they figured.

He ate meals alone. When housemates joined him he grew nervous and would leave the table.

"He wouldn't allow us to know him," McIntosh said. "At the same time, you had the impression that he was brilliant."

His room was full of trash. A fetid odor constantly emanated from it. Students had to ask the housemaster on several occasions to make him clean his quarters.

Late at night, with his door shut, Kaczynski practiced on his trombone.

Rustigan, the criminology professor, says of Kaczynski, "It's like there was a demon in this guy, something gnawing, something brewing. . . . Depression is almost always there in these brooding killers, along with paranoia and rage."

"A person is said to be well socialized if he believes in and obeys the moral code of his society and fits in well as a functioning part of that society." -- the manifesto, paragraph 24

The FBI thought they could discern, in the writings of the Unabomber, a man with a background in the history of science. But no one saw a mathematician, specifically. Mathematicians are focused on abstract truths; the Unabomber is focused on truths about the real world. The question is whether the Unabomber turned the real world into a kind of abstraction, into a system, a series of equations with variables and vectors, a thorough scrutiny of which would yield absolute, irreducible truths.

"Mathematics attracts a certain kind of person. Someone who feels comfortable with absolutes," said Donald Saranson, a Berkeley math professor who remembers the quiet, withdrawn Kaczynski. "Sometimes this carries over into real life. Sometimes they will interpret real events from a mathematical point of view, as an abstract system."

Keith Miller, another Berkeley colleague, said of mathematics, "You have to be able, for long periods, to push the world away, and concentrate."

Ted Kaczynski always excelled at math. Upon graduating with the Class of '62 at Harvard, Kaczynski took a position in the math department at the University of Michigan, making $2,300 a year as a "teaching fellow." He taught elementary collegiate math, such as calculus and analytic geometry. He worked on his advanced degrees.

At Kaczynski's level, mathematics is a language untranslatable into simple English concepts. This baffling Esperanto of symbols and signs is so abstruse that the layman is lucky to stumble across something as familiar-looking as a digit.

His dissertation was titled "Boundary Functions." It began:

"Let H denote the set of all points in the Euclidean plane having positive y-coordinate, and let X denote the x-axis."

It gets more complicated from there.

Peter Duren, a math professor who served on Kaczynski's dissertation committee, said that the paper was "pure mathematics" with no practical application. But it was also a terrific piece of work. Kaczynski was meticulous. During exams Kaczynski tended to offer more proof to math problems than was strictly necessary. He wrote in large, neat print, with big loops and precise margins.

Kaczynski's dissertation won the Sumner Myers Prize, given annually to the student who has produced the best mathematics thesis. He won it "hands down," says Maxwell Reade, one of five professors who grilled Kaczynski during his dissertation exam. Reade remembers that exam: The professors in chairs facing Kaczynski, who stood at the blackboard. The young math whiz "was self-composed, self-assured, answered everything, crossed every t, dotted every i, sailed right through it."

But there was something unusual about the dissertation: It lacked any acknowledgments. Kaczynski thanked no one. It's traditional for a doctoral candidate to thank his teachers, advisers, girl friend, or whomever.

"That says something about his feeling for other people," Reade said.

There's one other trait, quite flattering, that several math professors recall about Kaczynski. He was intellectually independent. He didn't wait for instructions. Kaczynski wrote a couple of mathematics treatises without telling anyone. They discovered Kaczynski's work only when it was published in academic journals.

The Unabomber writes of the significance of "autonomy."

"(F)or most people it is through the power process -- having a goal, making an AUTONOMOUS effort and attaining the goal -- that self-esteem, self-confidence and a sense of power are acquired. When one does not have adequate opportunity to go through the power process the consequences are . . . boredom, demoralization, low self-esteem, inferiority feelings, defeatism, depression, anxiety, guilt, frustration, hostility. . . . " -- the manifesto, paragraph 44

He arrived at Berkeley in 1967 as the Summer of Love was coming to a close. With his doctorate from Michigan he snapped up a tenure-track assistant professorship at the University of California-Berkeley, a place that could cherry-pick the best minds of his generation.

The campus was a "boiling cauldron" of political activity, mathematics department chairman John Addison recalled. The mathematicians as a group were deeply involved in the movement against the war in Vietnam.

But not Kaczynski. No one remembers Kaczynski expressing any political opinions. He did not join the antiwar movement. He had a teaching deferment then that kept him out of the draft. The same had been true back at Michigan. While other students marched and attended teach-ins, Kaczynski focused on his mathematics. He never opted for long hair and beads and sandals.

A photograph of Kaczynski circulated this week at Berkeley shows him in the late 1960s still wearing a jacket and tie, hair short, face neatly shaven. In the photo he is tight-lipped, his chin thrust out, his brows slightly furrowed. His eyes, deep-set, gaze intently into the camera.

He lived in those days in a tiny duplex apartment behind a house on Regent Street. A small jungle of vines and trees passes for a back yard. The main house in those days was occupied by people who worked or hung out at the free clinic in Berkeley. Even today there remain dozens of peace symbols etched into the sidewalk, slowly eroding.

His students apparently did not like him much. Student questionnaires described Kaczynski's lectures as "useless and right from the book," according to a student guide published at the time. One student evaluator wrote: "He absolutely refuses to answer questions by completely ignoring the students."

Kaczynski gave his boss a resignation letter on Jan. 20, 1969, effective at the end of the school year. Two senior faculty members called him to a meeting to discuss the startling decision. They remember Kaczynski as outwardly calm. But he didn't know what he wanted to do. He just wanted to leave the field of mathematics.

An explanation circulated within the Kaczynski family. Turk, Ted's father, told his buddy Ralph Meister that his son quit math because he didn't want to teach engineers how to build nuclear weapons.

Among the Berkeley math professors last week there was speculation that Kaczynski felt that mathematics was too removed from the real events of the day. "Sometimes it's hard to find a connection with the real world," said Saranson, one of the math professors. But Saranson, who is one of the few people who clearly remembers Kaczynski -- they had the same speciality, "complex variables" -- never heard his colleague utter a word about real-world events.

"Given a person who devotes much time and energy to the pursuit of goal X, ask yourself this: If he had to devote most of his time and energy to satisfying his biological needs, and if that effort required him to use his physical and mental faculties in a varied and interesting way, would he feel seriously deprived because he did not attain goal X?" -- the manifesto, paragraph 39

In the dissertation, "X" denotes the x-axis. For the Unabomber, did X denote mathematics?

He went to western Montana and built a cabin on raw land among the ponderosa.

He and his brother, David, had purchased about an acre and a half. The cabin was not much more than a shack, crafted from one-inch thick boards. While he built it, Kaczynski slept at night in a tent.

He had arrived in Montana with a pickup truck. He still has a valid driver's license. But three days after he arrived, the truck broke down, and he has since traveled either by foot or on his bicycle, going into the town of Lincoln five miles away to buy flour to bake his own bread. He gathered firewood from a nearby logging area. He took water from a stream running near his house.

"Electricity, indoor plumbing, rapid long-distance communications . . . how could one argue against any of these things? {Yet} all these technical advances taken together have created a world in which the average man's fate is no longer in his own hands . . . but in those of politicians, corporate executives and remote, anonymous technicians and bureaucrats whom he as an individual has no power to influence." -- the manifesto, paragraph 128

His new home was beautifully situated. The area is the setting for the book "A River Runs Through It" and some of the movie was filmed there. Kaczynski let environmental activists know that he appreciated their efforts to preserve the water quality of the Blackfoot River, but he said hardly anything else to them.

Kaczynski ignored the time obsession of modern civilization: He had no clock, no watch. When he had an appointment to keep he would venture down the road to the home of Butch and Wendy Gehring, explain his situation, and ask them to tell him when the correct day and hour had rolled around.

"There was instance when he was going to visit his brother a week later and wanted us to let him know when Thursday had come so he could catch his bus," said Wendy Gehring.

The Gehrings asked him why he was going to visit his brother. Kaczynski said it was none of their business. They protested that they were just curious. Kaczynski answered: "Curiosity killed the cat."

Don Shannon, pastor at the Lincoln Baptist Church, said that one morning at the town post office last summer he saw Kaczynski sitting on the concrete floor in a corner sifting through the reams of junk mail that residents had thrown away. He had made five immaculate piles of the discarded mail, each stacked according to size.

"He was just sitting there flat on the floor propping himself up against the wall with those piles around him like a large horseshoe. He was going out of his way to make sure each stack was nice and neat and that all the edges were straight," Shannon recalled. "Then he gently put all the piles in his knapsack."

With no job -- investigators believe he lived on occasional checks from his mother and brother -- Kaczynski would take whatever possessions he could get. Some of his clothes he got for free at the town's second-hand store. A fireman gave him a rickety bike assembled from parts of other bikes, the paint flaking away.

A census taker, Joe Youderian, set foot in the cabin in 1990 and glimpsed the spare life of Ted Kaczynski: A bed with rumpled covers, two chairs, a small table, a few trunks, a Coleman gas stove, a nail on the back of the door from which to hang a coat, and lots of books, including much classical literature, such as Shakespeare and Thackeray.

Kaczynski ordered out-of-print books from the local library. He read Scientific American and Omni magazines voraciously. Sometimes he hitched rides to Helena on a postal delivery truck and stayed in a $14-a-night hotel room. U.S. Postal Service driver Dick Lundberg recalls one time when Kaczynski said he was going to Helena to file documents for water rights so that he could use a natural spring on his property. But Kaczynski talked little.

"Everyone has goals; if nothing else, to obtain the physical necessities of life: food, water and whatever clothing and shelter are made necessary by the climate. But the leisured aristocrat obtains these things without effort. Hence his boredom and demoralization." -- the manifesto, paragraph 35

From Montana, "Teddy John" wrote Ralph Meister, his father's friend, a few letters, including one in which he asked for information about the Inca civilization. Meister once sent the reclusive former mathematician a math puzzle that Meister had invented. Kaczynski wrote back: "Your concepts are too imprecise."

Meister recalls that "Turk" Kaczynski visited his son several times in Montana, camping out together in the woods. The elder Kaczynski admired his son's woodsmanship, his ability to build a lean-to, his talent at knowing from the look of the sap which branches would burn well.

On the whole, there is little documentary evidence so far of what Kaczynski has been doing for the past quarter of a century. In 1977, the Harvard University 15th Anniversary Report gave Kaczynski's address as 1001 Sixth Ave., Apt. 4, in Great Falls, Mont. There have been unconfirmed reports that Kaczynski worked construction jobs for a while in the early 1980s in Utah.

Kaczynski's father was diagnosed with lung cancer in 1990. Tumors were also found on the elder man's back. An independent, self-reliant man, he put his affairs in order, held a family meeting to discuss the future -- with Ted absent, apparently -- and then on Oct. 2, 1990, killed himself with a .22-caliber rifle.

Ted never came home.

Rustigan, the criminologist, says of Kaczynski, "Once he kissed off mathematics, there was this huge void because he had no friends, no love life, no support system. Mathematics had been his whole identity. In so many of these cases, your self-esteem comes from one source; if the plug is pulled on this, it's like the person does not have a life. . . . It appears that he is estranged from the human race."

The Unabomber in the late 1970s became more than merely estranged from the species: He went on the attack.

"We have no illusions about the feasibility of creating a new, ideal form of society. Our goal is only to destroy the existing form of society." -- the manifesto, paragraph 182

The FBI would later marvel that the Unabomber meticulously handcrafted virtually every element of his bombs, even parts that could easily have been purchased at a hardware store. In one of his letters he bragged that he not only wiped his bombs clean of fingerprints but also sanded them to remove any subsurface oils that might have seeped into the wood and metal.

The first two bombs exploded at Northwestern University in Evanston, Ill. No one was seriously hurt. But then the bomber tried to blow up a plane. He failed, but a dozen passengers were treated for smoke inhalation.

"The idea was to kill a lot of business people who we assumed would constitute the majority of the passengers," the Unabomber wrote in letter last year to the New York Times. "But of course some of the passengers likely would have been innocent people -- maybe kids, or some working stiff going to see his sick grandmother. We're glad now that that attempt failed."

The Unabomber's war was peculiar for being so completely inexplicable. The Unabomber was silent for the first 17 years of his campaign. The FBI didn't know who or what they were dealing with. They called the bomber UNABOM, since his targets were linked to universities and airlines. The media dubbed him the "Unabomber."

The investigation originally was decentralized, handled by various field agents of the FBI. For one six-year period, from 1987 to 1993, the Unabomber seemed to go into hibernation, with no known bombings anywhere. Three years ago, however, two prominent university professors were injured by mail bombs. The FBI expanded its investigation. With the fatalities in 1994 and 1995 and the appearance of the manifesto the case hit a new level of intensity. Hundreds of agents checked out tens of thousands of tips. The break came when David Kaczynski began to see links between letters written by his older brother and the bomber's manifesto. He retained a Washington attorney, Anthony P. Bisceglie, who contacted the FBI.

In Montana, agents watched Kaczynski for a month before descending on the cabin last Wednesday.

The alleged Unabomber was lying on a cot.

"Ted, we need to talk," an agent reportedly told him.

What Ted Kaczynski thought at that moment -- or thinks now, locked up in the Lewis and Clark County Jail -- is unknown.

"Freedom means being in control (either as an individual or as a member of a SMALL group) of the life-and-death issues of one's existence; food, clothing, shelter and defense against whatever threats there may be in one's environment." -- the manifesto, paragraph 93

He has made no public statement, other than to say, when asked if he had no money to afford a lawyer, "quite correct." He has been pacing in his cell, the sheriff says. He's eating. He's reading the newspapers. And he's obtained some books from the jailhouse library.

Staff writers Thomas Heath, John Schwartz, William Claiborne, Jacqueline Salmon, Pierre Thomas, Edward Walsh and Lorraine Adams and researcher Alice Crites contributed to this report.

CAPTION: THEODORE KACZYNSKI: From Academe To Bald Mountain 1942

- May 22, 1942: Unabomber suspect Theodore John Kaczynski is born in Chicago, to Theodore R. and Wanda Kaczynski.

  • 1952 Kaczynski family moves to Evergreen Park, a middle-class Chicago suburb.

  • 1955-58 Attends Evergreen Park Community High School. Kaczynski skips a grade in elementary school and again in high school, graduating at age 16 as a National Merit Scholarship finalist.

  • 1958-62 Attends Harvard on scholarship, earning BA in mathematics.

  • 1962-67 Graduate student at University of Michigan at Ann Arbor, completing MA, then PhD, in math with dissertation on "Boundary Functions." Attends Harvard on scholarship, earning BA in mathematics. - 1969 Jan. 20: Resigns from the University of California at Berkeley, effective June 30, 1969, after teaching mathematics since 1967. - 1971 June: Kaczynski and brother, David, buy property on Bald Mountain near Lincoln, Mont. Theodore builds cabin during visits to his remote tract. In 1972, he gives his address to Harvard as Lombard, Ill., but he also lived and worked in the Salt Lake City area sometime in the 1970s, according to federal authorities.

  • 1978 May 25: Package found in parking lot at University of Illinois at Chicago is brought to Northwestern University in Evanston because of return address. A day later it explodes when opened, injuring Terry Marker, a security guard.

  • 1979 May 9: John Harris, a graduate student, is injured in blast at Northwestern University.

  • Nov. 15: Bomb explodes in plane's cargo hold during American Airlines flight, injuring 12 with smoke inhalation and forcing emergency landing at Dulles International Airport.

  • 1980 June 10: Package bomb injures United Airlines president Percy Wood at home in Chicago area.

  • 1981 Oct. 8: Bomb found in business classroom at University of Utah in Salt Lake City is safely defused. No injuries.

  • 1982 May 5: Janet Smith, secretary, injured at Vanderbilt University in Nashville; package bomb was addressed to Patrick Fischer, a computer science professor.

  • July 2: Diogenes J. Angelakos, professor of electrical engineering and computer science, injured in faculty lounge at University of California at Berkeley.

  • 1985 May 15: John Hauser, a graduate student in electrical engineering, injured by bomb found in computer room at University of California at Berkeley.

  • June 13: Package bomb mailed to Boeing Co. in Auburn, Wash., is discovered and safely disarmed.

  • Nov. 15: Psychology professor James McConnell and his assistant, Nicklaus Suino, are injured by bomb addressed to McConnell at the University of Michi-gan at Ann Arbor.

  • Dec. 11: Hugh Scrutton killed in bomb explosion near his computer rental store in Sacramento. 1987 Feb. 20: Gary Wright is injured by bomb left near his computer shop in Salt Lake City. A Unabomber sighting and description leads to familiar police sketch of hooded figure wearing sunglasses.

  • 1993 June 22: Charles Epstein, geneticist at University of California at San Francisco, is injured by bomb sent to his home.

  • June 24: David Gelernter, computer scientist at Yale University, is injured in office blast.

  • 1994 Dec. 10: Advertising executive Thomas Mosser killed by bomb sent to his North Caldwell, N.J., home.

  • 1995 April 24: California Forestry Association president Gilbert P. Murray killed opening package bomb mailed to the group's Sacramento headquarters.

  • June: Unabomber sends 35,000-word manifesto calling for abolition of modern society to The Washington Post and the New York Times. Threatens to bomb an unspecified location if it is not published within three months.

  • June 28: In letter to San Francisco Chronicle, Unabomber threatens attack on a flight out of Los Angeles International Airport, prompting heightened security, delays at airports statewide.

  • Sept. 19: Advised by the Unabomber that publication would stop attacks, The Washington Post and the New York Times publish the 35,000-word manifesto.

  • 1996 April 3: Theodore J. Kaczynski detained after brother's tip leads FBI to stakeout, search of Montana shack, and discovery of partially constructed bombs, bomb diagrams.

  • April 4: Kaczynski is charged with a federal weapons violation.

CAPTION: At top, a photo of suspect Theodore J. Kaczynski and police sketch of the terrorist. At bottom is package in which the Unabomber sent treatise to The Washington Post.

CAPTION: Authorities are comparing documents of Theodore J. Kaczynski such as th letter at top from graduate school days at University of Michigan and and a section from his dissertation, center, with known Unabomber writings like diagram, at bottom, from the 35,000 word "manifesto" published last year.

CAPTION: FBI has blocked route to Kaczynski's mountain cabin as forensic specialists examine the property for evidence linking him to Unabomb attacks.

CAPTION: In Helena, Mont., Thursday, Kaczynski is surrounded by officers who take him to federal court where he was charged with possession of bomb components.

CAPTION: Kaczynski (far left) as a child

CAPTION: Kaczynski in 1962

CAPTION: Kaczynski's Montana cabin

CAPTION: Kaczynski in 1996