The lick of a stamp may prove to be the Una-bomber's undoing.
Investigators building a case against former university professor Theodore Kaczynski, suspected in a series of bombings that killed three people and maimed 23, are conducting DNA analysis on specks of dried saliva found on postage stamps used to mail the Unabomber's deadly packages, U.S. officials say.Experts hope that "genetic fingerprinting" - an advanced science that entered the public spotlight during the O.J. Simpson murder trial - will yield evidence linking Kazcynski to the Una-bomber's 16 attacks.
"The DNA aspect of the investigation could be key," one law-enforcement source said. "This is a classic example of a case that requires all types of investigation, including forensics evidence."
Kaczynski, a 53-year-old mathematician, was being held in Helena on one count of possessing bomb-making components, which were found in his remote mountain cabin. He has not yet been charged in any of the Unabomber attacks.
For investigators who have spent 17 years tracking the elusive bomber, even specks of dried saliva may prove critical.
A technique known as polymerase chain reaction, which was developed in the 1980s, allows in-vestigators to amplify scraps of DNA found in saliva left on stamps and envelopes.
The procedure may allow Una-bomber investigators to link Kaczynski to DNA left on the Unabomber's packages and on letters sent to news organizations.
The bomber often sent his meticulously hand-crafted bombs through the mail. To make the match, hair or blood found at Kaczynski's cabin could be used, experts say. A suspect was linked to the World Trade Center bombing through DNA analysis of an envelope. DNA on a stamp linked a former nursing home worker to the rape and pregnancy of a comatose woman in New York.