WASHINGTON (AP) _ The names of Unabomber victims have turned up in Theodore Kaczynski's writings found at his wilderness cabin, and federal agents have discovered possible casual contacts between him and four victims, officials said Tuesday.

These were among a mounting list of apparent links between the reclusive, 53-year-old former mathematics professor and the Unabomber's 18-year string of bombings as investigators settled into what one called ``a painstaking, methodical investigation that will take weeks.''

``There is a general consistency in the written plans and the physical evidence found at the cabin scene, with the Unabomber's work,'' said a law enforcement official in Washington, commenting only on condition of anonymity.

``The names of some victims were found in the cabin,'' he said, declining to disclose them or in what form they appeared.

A second federal law enforcement official said the notebooks that Kaczynski wrote by hand and some printed material at the cabin near Lincoln, Mont., do mention some of the Unabomber's victims but also include references to many other individuals and organizations.

Most of the references are handwritten but none specifically mentions Unabomber victims as targets, the second official said. ``The idea that there is a list of victims or targets is not correct.''

Elsewhere, federal agents scouring the Unabomber's suspected haunts and target sites across the nation have turned up evidence that Kaczynski may have actually crossed paths with four Unabomber victims, according to a federal law enforcement source. Three people have been killed and 23 injured in nine states in Unabomber attacks.

These are the possible casual contacts:

_Hugh Scrutton, killed in his Sacramento Calif., computer store in 1985, took classes in the University of California at Berkeley math department when Kaczynski taught there in the late 1960s, the source said.

_Vanderbilt University computer science professor Patrick Fisher, wounded by a 1982 bomb, frequently visited his father, a math professor at the University of Michigan when Kaczynski was a graduate student in that department.

_James McConnell, wounded in a 1985 attack, was a psychology professor at the University of Michigan when Kaczynski was a student there.

_United Air Lines President Percy Wood, wounded in a 1980 bombing, was a member of the Bay Area Air Pollution Control Board advisory committee when Kaczynski was teaching in the same area at Berkeley.

Those interviewed so far remember mostly hallway encounters or casual contact with Kaczynski rather than any close association, the source said. Other victims are being checked for similar possible contacts.

Meantime, officials were growing more and more confident that they will be able to make a case that Kaczynski, so far charged only with possessing bomb components, is the Unabomber.

There was a meeting Monday at the Justice Department with federal prosecutors from seven states where there has been Unabomber activity. At that preliminary discussion, Sacramento and northern New Jersey emerged as the leading sites for a federal Unabomber prosecution because two killings, in 1994 and 1995, occurred there after the federal death penalty was restored to laws that might apply, a federal official said.

No final decisions will be made until all the evidence can be examined, this official said.

Lab work has begun on tools taken from the Kaczynski cabin, two officials said. The tools are being painstakingly compared with scraps of wire, wood and metal taken from the Unabomber's devices over the years. ``Every tool that has been used leaves marks as distinctive as a fingerprint,'' one official said.

Three federal sources told The Associated Press that one live bomb, along with a partially assembled one agents had described in an arrest warrant, had been found in the cabin. The devices were made from the same type of materials the Unabomber used, one official said.

The FBI has said that 10 three-ring binders full of bomb sketches were found in the cabin along with three rolled logs of pipe bomb experiments. These writings appear to be consistent with the Unabomber's work, one official said.

Also found at the cabin were two manual typewriters, one of which appears to have been used to type Unabomber letters and his 35,000-word manifesto, law enforcement sources have said.

Elsewhere, federal agents combed cities across the nation for evidence that Kaczynski traveled to locations where bombs were placed or mailed.

A law enforcement source said Kaczynski stayed in Sacramento hotels at times when letter bombs attributed to the Unabomber were mailed from the city.

In Sacramento and elsewhere, agents have carted away guest registration cards from hotels and motels. ``We'll check those registration cards for handwriting samples and fingerprints,'' said one federal investigator.

Meanwhile, a computer search by the Internal Revenue Service turned up no sign that Kaczynski has filed any income tax returns since he left teaching in 1969 and began living as a hermit, an IRS source said, speaking on the condition of anonymity.

Federal law currently does not require single people who make less than $6,400 a year to file income tax returns. A neighbor has said Kaczynski once told him he lived on $200 to $300 per year.

Earlier, it was reported that Kaczynski filed for a state property tax credit that is available to people who earn less than $15,000 per year.

___

EDITOR'S NOTE _ Associated Press Writer Richard Cole in San Francisco contributed to this story.