Ted Kaczynski was convicted of several bombings between 1978 and 1995. Three people were killed and about 20 injured in the Unabomber's 16 different bombings.
In a manifesto published by The Washington Post and The New York Times, he denounced technology and modern development. His brother recognized wording in the manifesto and tipped off the police. He was sentenced in 1996 to life imprisonment without parole. The cause of death is yet to be determined, a prison spokesperson said. The former mathematician and university lecturer was 81.