BOMBING SUSPECT OUTLINED ANGER, DREAMS IN LETTERS.

Byline: James Brooke with David Barboza The New York Times

Barely two years ago, Theodore John Kaczynski, the man suspected of being the Unabomber, raged against government officials, portraying them as ``either stupid and incompetent, or liars who twist the law to commit any injustice.''

At the same time, Kaczynski, writing to a Mexican farmhand with whom he had maintained a seven-year-long correspondence, shared his longing for a different life than the solitary existence he led in a remote cabin in the mountains of Montana.

Replying to a complaint from the farmhand, Juan Sanchez Arreola, about Sanchez's difficulty in resolving a pension dispute with the Mexican government, Kaczynski wrote in May 1994: ``Although what the officials are doing is a great injustice, consider that your fortune is not all bad, because you have a wife and three children and all are healthy.

``Even though you have to endure these difficulties, you will probably overcome them in the end, and your children will thrive and some day they will have children of their own. I wish I had a wife and children!''

The remarks were contained among three more letters - two of them dated in 1995 and one in 1994 - handwritten in Spanish by Kaczynski and discovered Wednesday by the 68-year-old Sanchez after he searched a sun-baked house trailer that he keeps on a ranch in this remote West Texas town.

These letters, along with two others that Sanchez found earlier in his home in the town of Ojinaga, Mexico, just across the Rio Grande from Presidio, Texas, are believed to be all that remains of the correspondence between the two men. Although they never met one another, Kaczynski wrote about 50 letters to Sanchez after initiating the correspondence in 1988.

After an exhaustive search of the trailer and property, Sanchez, making a tearing motion with his hands, said he had thrown away most of the other letters over the years.

Since Kaczynski's arrest last week, FBI agents have spread out across the nation, looking into his past and attempting to compare his movements and actions to what they know about the 18-year-long bombing spree carried out by the serial bomber known as the Unabomber. The bombing campaign killed three people and wounded 23.

They also have been interviewing his friends and neighbors in an effort to reach a better understanding why he might have become the Unabomber.

Among other things, federal officers searching Kaczynski's cabin in Montana have discovered evidence of hand-made screws, among the growing inventory of physical items taken away by agents. The screws are regarded as especially tantalizing pieces of evidence, if agents are able to match those screws to fragments found in the debris of bombs made by the Unabomber.

In another development, law enforcement officials said Wednesday that sophisticated tests conducted on two typewriters found early in the search of the Montana cabin had led them to discount the likelihood that either machine had been used to type the Unabomb manifesto.

But they said that a third typewriter had been found. The officials said they were hopeful, based on preliminary tests, that this typewriter would prove to be the one used to write the manuscript published last year in The Washington Post and financed by The Post and The New York Times.

The letters uncovered Wednesday, handwritten on the same blue-lined, three-ring binder paper that the FBI says was used to record bomb-making instructions, add to the emerging portrait of the loneliness, anger and poverty of Kaczynski.

Over the past decade, Sanchez gradually became a confidant of the Kaczynski family, first winning the friendship of David Kaczynski, Theodore's younger brother. Wednesday, as a sign of the long friendship, a sun-faded, 30-year-old van that once belonged to David Kaczynski sat parked on Sanchez's trailer lot in Terlingua.

In 1984, David bought a 30-acre lot in the mesquite-covered desert here, within sight of the bone-dry flanks of the Chalk Mountains. With the help of Sanchez, he built a small cabin and a catch basin for rainwater.

Sanchez made the correspondence available to The New York Times, after an examination of mortgage papers in New York led to David Kaczynski's property here. John C. Rosson, a neighbor, told reporters about the relationship between Sanchez and the Kaczynskis.

The FBI says it is aware of the correspondence, although agents have not yet interviewed Sanchez.

``David didn't say much more about his brother than that he had a brother,'' said Rosson, a retired General Motors millwright who owns a small ranch in Terlingua.

With only a trailer without water or electricity as an improvised residence in Terlingua, Sanchez used Rosson's post office box in Alpine, Texas, as his U.S. mailing address. Alpine is about 80 miles north of Terlingua.

The letters represent the first evidence that Kaczynski maintained any sustained relationship in the years after he retreated to the cabin in Montana. Written in a studiously formal Spanish - Kaczynski ritually addresses Sanchez as ``my very dear and esteemed friend'' - the letters offer a catalog of complaints, comments about the weather and the mountain landscape, and even a detailed description of how to stalk and hunt rabbits.

They also testify to Kaczynski's loneliness and poverty. Indeed, an examination of one of the envelopes shows that once, to save 29 cents in postage, Kaczynski glued a used stamp on a new envelope.

``Don't hold out great hope that I can go visit you for Christmas,'' Kaczynski wrote in pencil in the May 1994 missive. ``Things are going badly for me. I still don't have a job, and without work there is no money and without money there is no bus ticket.''

Writing from his casita or little house, Kaczynski repeatedly lamented a hand-to-mouth existence.

``I badly need money, and here there is no work in the winter,'' he wrote Feb. 17, 1994. ``The best season for work is the summer, so the best season to look for work is the spring, and so I should be around here to look for work.''

``Because if I don't get work for next summer, I will die of hunger when winter comes,'' he concluded, explaining why he was, once again, declining Sanchez's invitation to come south.

In Lincoln, Mont., last week, residents said Kaczynski performed occasional odd jobs. Last year, he was turned down for a job as a grocery checkout clerk, largely because of his unkempt appearance.

Sanchez, whose thick fingers speak of a lifetime of manual labor, reacted dismissively Wednesday, saying: ``In Mexico, we have one word for people like that - perezosos - lazy!''

In return letters, laboriously printed, the barely literate Mexican answered Kaczynski's questions about the Mexican Revolution and about his own 68 years in this austere land of cactus, mesquite thorns and dusty flowers.

While Sanchez said he sometimes chuckled appreciatively at Kaczynski's written railings against ``soulless and lying officials,'' he said he was unnerved by the North American's alienation from his family.