-- Jan 22, 1998: Theodore Kaczynski pleads guilty in Sacramento, Calif., to being the Unabomber in return for a sentence of life in prison without parole. He's locked up in the federal Supermax prison in Colorado for killing three people and injuring 23 during a nationwide bombing spree between 1978 and 1995.
-- Jan. 20, 1998: A bombing at an abortion clinic in Birmingham, Ala., kills one guard and injures a nurse. Eric Robert Rudolph is suspected in the case.
-- July 27, 1996: A bomb explodes at Centennial Olympic Park in Atlanta during the Summer Games, killing two people and injuring more than 100. Eric Robert Rudolph is arrested in 2003. He pleads guilty and is sentenced to life in prison.
-- April 19, 1995: A car bomb parked outside the Murrah Federal Building in Oklahoma City kills 168 people and injures more than 500. It is the deadliest U.S. bombing in 75 years. Timothy McVeigh and Terry Nichols are convicted. McVeigh is executed in 2001 and Nichols is sentenced to life in prison.
-- Feb. 26, 1993: A bomb in a van explodes in the underground World Trade Center garage in New York City, killing six people and injuring more than 1,000. Five extremists are eventually convicted.