THE MOUNTING EVIDENCE

The third typewriter was the lucky one. When federal agents raided the 10-ft. by 12-ft. shack of Unabomber suspect Theodore Kaczynski two weeks ago, they were overjoyed to find two old manual machines, relics of the pre- word processor, pre-Selectric age. Surely, one of these must be the antique on which the bomber pecked out his 35,000 word opus, Industrial Society and Its Future. In straight-faced leaks over the next week, the agents let it be known that, alas, the typefaces did not match, although they had high hopes for a third typewriter, discovered later. What they did not mention was that nestled next to that third machine in Kaczynski's loft was something that made lesser discoveries moot: a manuscript of the manifesto itself.

You may not hear the cheering publicly, since FBI head Louis Freeh is livid that the news was leaked. But do not doubt that hundreds of federal and state investigators, caught up for weeks in the frustrating experience of trying to square the past 18 years of Kaczynski's life with the Unabomber's attacks, are celebrating the discovery of the manifesto amid a mother lode of incriminating evidence. Last Thursday, when the Justice Department named New Jersey First Assistant U.S. Attorney Robert J. Cleary to lead the team that will prosecute Kaczynski, the hot speculation was over whether the initial prosecution would take place in Cleary's state, where the Unabomber murdered advertising executive Thomas Mosser in 1994, or in California, where timber lobbyist Gilbert Murray was killed in 1995. Prosecutors could seek the death penalty in either case.

Up until the search of Kaczynski's cabin, federal authorities were not totally sure that the Lincoln hermit was their man. No one had ever seen Kaczynski mail a bomb. Several clues the Unabom task force has long held in hand are not foolproof. The few fingerprints recovered from the Unabomber's efforts, say investigators, are missing the central whorls; even if Kaczynski's matched, a jury might not be persuaded. Unknown to many, the bombs had yielded bits of hair and fiber, but the cops could not be sure they were the perpetrator's. Nor were they sure they had collected enough DNA from the bomber's stamps and parcels to match the suspect's saliva.

Hence their satisfaction about what turned up in the cabin, even before the manuscript surfaced. In addition to the bombmaking notes and paraphernalia and the half-made bomb they found immediately, agents soon encountered a finished product: they had to delay the search while they defused it. Its structural peculiarities, experts said, were exactly those of the Unabomber bombs. The searchers also discovered a piece of paper with the words "hit list" written above "airline industry," "computer industry" and "geneticists." Evidence from the cabin was so strong, federal officials said, that it might convict Kaczynski without having to match his whereabouts with the bomber's at the time of the crimes.