SAN FRANCISCO -- In a previously undisclosed letter received this week by one of his victims, the "Unabomber" ridiculed the man as a "techno-nerd" and blamed him for promoting a "computer-dominated world."
"People with advanced degrees aren't as smart as they think they are," the serial bomber told computer science professor David Gelernter, who was maimed in June 1993 when he opened a letter bomb at his Yale University office. "If you'd had any brains you would have realized that there are a lot of people out there who resent bitterly the way techno-nerds like you are changing the world and you wouldn't have been dumb enough to open an unexpected package from an unknown source."
The letter was postmarked April 20 and bore as a return address the location of the FBI's Washington, D.C., headquarters.
It was released yesterday by Jim Freeman, special agent in charge of the FBI's San Francisco office and head of the federal Unabom task force.
Mr. Freeman said at a press conference he was releasing the letter in the hope that something in it will produce the lead that finally ends the 17-year string of 16 bombings that has left three dead and 23 injured.
"We're looking for a piece of luck, that tip from the public, to solve this case," he said.
The letter to the Yale professor is one of four missives the previously taciturn Unabomber mailed out four days before his latest bombing on Monday killed Gilbert F. Murray, president of the California Forestry Association. Mr. Murray died when he opened a package delivered to his Sacramento office.
One of the other letters, all of which were authenticated by an undisclosed nine-digit number issued earlier by the Unabomber, was sent to the New York Times. The other two were sent to individuals whom Mr. Freeman declined to identify. He said they were not previous victims or in any other way linked to the investigation.
In his letter to the Times, the Unabomber claimed to be part of an anarchist group -- a claim that the FBI does not believe -- that is bent on dismantling industrial society. He offered to end the campaign of terror if arrangements are made to prominently publish the alleged group's lengthy manifesto, but reserved the right to commit sabotage.
The letter to the Yale professor was more personal and vindictive.
"In the epilog of your book, 'Mirror Worlds,' you tried to justify your research by claiming that the developments you describe are inevitable, and that any college person can learn enough about computers to compete in a computer-dominated world," he wrote. "Apparently, people without a college degree don't count."
The Unabomber, so named because his early victims were related to universities and airlines, took the professor to task for arguing in his book that technological evolution is inevitable.
"As for the inevitability argument, if the developments you describe are inevitable, they are not inevitable in the way that old age or bad weather are inevitable," the Unabomber wrote. "They are inevitable only because techno-nerds like you make them inevitable."