[0] UNABOMBER SUSPECT HELD : FBI DETAINS EX-PROFESSOR AFTER TIP FROM FAMILY LED TO MONTANA STAKEOUT.

Byline: David Johnston The New York Times

Federal agents on Wednesday detained in Montana a man they suspect of being the Unabomber, the terrorist who has left an 18-year-long trail across the United States of bombs that have killed three people and maimed 23 others.

The suspect, Theodore Kaczynski, 53, is a former assistant professor of mathematics at the University of California at Berkeley who graduated from Harvard University and received a doctorate from the University of Michigan - just the sort of settings in which the authorities had been hunting for the bomber.

Since the early 1970s, Kaczynski has lived in a tiny, hand-built cabin northwest of Helena, Mont., near the Continental Divide on the edge of Lolo National Forest, an area so remote that one of the FBI agents who kept him under surveillance there is said to have watched a cougar attack and kill a deer.

The authorities confronted Kaczynski at the cabin Wednesday and, after a brief scuffle, searched it for evidence of bomb-related material. It was not clear Wednesday night what they had found.

The FBI put Kaczynski under scrutiny about two months ago, when - after years of fruitless searching across the country, false leads and the publication of a 35,000-word manifesto from the bomber - the long-awaited breakthrough came from the most ordinary of sources: Members of Kaczynski's family in the Chicago area, apparently while cleaning house, discovered writings that seemed strikingly similar to the Unabomber's anarchist tracts.

His family turned the papers over to the FBI, apparently relying on a relative, a Washington lawyer, as an intermediary. Members of the family permitted the FBI to search their house, and, officials said, further evidence against Kaczynski was found.

While law-enforcement officials said they strongly suspected Kaczynski, he was not placed under formal arrest Wednesday. Having been detained outside his home after a scuffle with agents who were trying to serve a search warrant on him, he was neither booked nor fingerprinted.

And although he remained under detention, his whereabouts were unclear Wednesday night.

But some officials said they expected that he would be formally charged with the bombings, and government lawyers prepared to announce his arrest. These officials said they had uncovered evidence that could link him to the bombings through fingerprints, typewriter imprints, unexploded devices and DNA analysis of saliva recovered from stamps that the bomber used to mail letters to his victims and to news organizations.

Kaczynski was reared in Evergreen Park, Ill., a working-class suburb of Chicago that Wednesday offered a tableaux of Middle American images, from the Kaczynski family's brick colonial house, flanked by two elm trees, to the nearby neighborhood park, where children played soccer and touch football.

A spokesman for Harvard University, Alex Huppe, said that Kaczynski graduated from Harvard College in 1962 and earned his bachelor's degree majoring in mathematics.

Professor Maxwell O. Reade, the associate chairman for graduate students at the University of Michigan mathematics department in the late 1960s and most of the 1970s, now retired, said Kaczynski had written his doctoral thesis in the mathematical area known as modern analysis. The thesis covered ``boundary properties of spaces and functions,'' Reade said.

The Unabomber began his reign of mayhem in May 1978 and delivered his last bomb in April 1995, his meticulously built devices growing ever more powerful and lethal and his communications to the authorities more menacing.

In an effort to showcase his anti-technological ideology, the Unabomber last year sent The New York Times a 35,000-word manuscript that railed against what he described as the corrupt and dehumanizing influences of post-industrial society. Academics said the writing conveyed passable but unoriginal thinking about subjects like the history of science.

After the Unabomber had pledged to cease his campaign of violence if the Times or The Washington Post published his manifesto, the two newspapers jointly financed the publication of the manuscript by the Post in September. Later it was distributed widely through computer networks.

The manifesto, and a false threat in California to blow up a plane, prompted some criminal profilers to alter their view of the bomber, seeing him not as a terrorist with a political grudge but as a serial killer whose bombs fulfilled an inner psychological need.

In the government's hunt for a suspect, vast lists were culled by computer, a telephone line received more than 20,000 tips, and new investigative technologies were perfected to sift huge databases of information.

But the years of effort proved fruitless until investigators received what they said was the vital clue, the tip from a family member about two months ago.

In the following weeks, Kaczynski's cabin was under continuous hidden surveillance by federal agents who stood watch through blizzards that periodically raked the rugged region.

Throughout the surveillance, Kaczynski remained at the cabin, a 10-by-12-foot dwelling that has no electricity or running water. He chopped his own wood for heat and kept a cache of food in a root cellar.

Although he had lived as a recluse, Kaczynski did seem to fit the government's profile of the man who had been one of its top fugitives from justice and the subject of a vast inquiry involving hundreds of federal agents headquartered in San Francisco.

As the FBI's profile had predicted, Kaczynski was a loner, had lived in the Chicago area, was well-educated and had once lived in northern California. At one time, the Harvard alumni magazine reported that Kaczynski lived in Afghanistan, in a small town southwest of the Khyber Pass, which was popular with Westerners who sought high desert scenery, timeless villages and easy access to drugs.

For years, the Unabomber had remained a shadowy figure, known to the public only from the FBI's composite drawing of a gaunt man wearing aviator sunglasses staring out under the hood of a sweat shirt. His personality only became more boldly defined through his manifesto.

LIST OF BOMBINGS Bombings linked to the so-called Unabomber. The FBI gave the case the code name ``Unabom'' because early targets were universities and airlines.

May 25-26, 1978: A package is found at a parking lot at the University of Illinois at Chicago and brought to Northwestern University in Evanston because of the return address. It explodes when it is opened on May 26, injuring one person.

May 9, 1979: One person injured at Northwestern University.

Nov. 15, 1979: Twelve suffer smoke inhalation when bomb explodes in plane's cargo hold during American Airlines flight, forcing an emergency landing at Dulles International Airport near Washington.

June 10, 1980: United Airlines president injured at home in Chicago area.

Oct. 8, 1981: Bomb placed in a business classroom at University of Utah in Salt Lake City. No one injured.

May 5, 1982: One person injured at Vanderbilt University in Nashville; package addressed to a professor.

July 2, 1982: Professor of electrical engineering and computer science injured in faculty lounge at University of California at Berkeley.

May 15, 1985: One person injured by bomb found in computer room at University of California at Berkeley.

June 13, 1985: Package that was mailed to the Boeing Co. in Auburn, Wash., on May 8 is discovered and safely disarmed.

Nov. 15, 1985: Two people injured by package mailed to professor at University of Michigan at Ann Arbor. The professor, who was standing nearby, wasn't hurt.

Dec. 11, 1985: Hugh Scrutton, 38, killed by bomb found near his computer rental store in Sacramento, Calif.

Feb. 20, 1987: Man injured by bomb left behind computer store in Salt Lake City.

June 22, 1993: Geneticist at University ofF California at San Francisco injured by bomb sent to his home.

June 24, 1993: Yale University computer scientist injured in office.

Dec. 10, 1994: Advertising executive Thomas Mosser, 50, killed by bomb sent to his North Caldwell, N.J., home.

April 24, 1995: California Forestry Association President Gilbert P. Murray, 47, killed opening a mail bomb in the group's Sacramento headquarters.

SOURCE: Associated Press

CAPTION(S):

2 Photos, box

PHOTO (1 -- color) Theodore Kaczynski

Has doctorate in mathematics

(2) no caption (FBI composite drawing of the man known as the Unabomber)

BOX: List of bombings