Attack: Dec. 21, 1988
Soon after takeoff, plastic explosives hidden in a suitcase detonate aboard Pan Am Flight 103 from London to New York City, killing all 259 on board and 11 on the ground in Lockerbie, Scotland. Among the passengers and crew are 189 Americans.
Breakthrough: October 1990
For nearly two years, U.S. investigators had been focusing on the theory that Iran hired a Syrian-sponsored terrorist group to take down the plane. Then reports break that U.S. officials have linked a timer fragment found at the crash site to timers seized from Libyan intelligence agents just months before the crash.
Capture: April 5, 1999
In 1991, U.S. investigators indict two Libyans for the attack: Abdel Basset Ali al-Megrahi and Lamen Khalifa Fhimah. But it takes years of sanctions and international pressure for Libyan officials to hand over the suspects. Both are tried in a neutral country, the Netherlands, under Scottish law. In 2001, al-Megrahi is found guilty and Fhimah is acquitted.