Theodore "Ted" Kaczynski
The 18-year search for the Unabomber was the U.S.'s longest and most expensive hunt for a serial killer. Ted Kaczynski, a brilliant mathematician accepted to Harvard at age 16, sent 16 bombs — handcrafted with wooden parts — across the country from 1978 to 1995, killing three and wounding 23. Despite an accurate psychological profile, a $1 million reward and extensive forensic investigation, the FBI couldn't get a handle on the case. It took the 1995 publication of his rambling manifesto in the New York Times and the Washington Post for the bomber to be located: Kaczynski's brother David recognized the prose and tipped off the police. Kaczynski was arrested on April 3, 1996, at his Montana log cabin. He is serving a life sentence in prison without the possibility of parole. His brother still writes him monthly, without reply.