Summary of events in the case of convicted Lockerbie bomber Abdel Baset al-Megrahi:
Dec. 21, 1988: Pan Am Flight 103, heading to New York from London's Heathrow airport, explodes over Lockerbie, Scotland. The explosion kills 259 people on board, and 11 on the ground.
Nov. 14, 1991: U.S., Scottish authorities indict two Libyan intelligence officials — Abdel Baset al-Megrahi and Amin Khalifa Fhimah — in the bombing.
Jan. 21, 1992: U.N. Security Council demands Libya hand over al-Megrahi and Fhimah, but a Libyan judge later that year rejects extradition demands.
Dec. 11, 1996: Megrahi insists he is innocent and says he is willing to stand trial in a neutral country.
May 3, 2000: Trial on charges of conspiracy and murder opens at Camp Zeist in the Netherlands under Scottish law.
Jan. 31, 2001: Al-Megrahi found guilty and jailed for life. Fhimah is acquitted.
Jan. 23, 2002: Al-Megrahi appeal begins, but judges later uphold the conviction.
Aug. 15, 2003: Libya officially accepts responsibility for Lockerbie, agrees to pay restitution to relatives of victims.
Sept. 12, 2003: U.N. Security Council approves lifting U.N. sanctions against Libya.
March 2004: Former Prime Minister Tony Blair meets Libyan leader Muammar al-Qaddafi in a tent outside Tripoli and offers the "hand of friendship."
Feb. 24, 2005: Al-Megrahi is moved to Greenock prison in Scotland.
Oct. 21, 2008: Al-Megrahi is diagnosed with prostate cancer.
April 28, 2009: Al-Megrahi begins his second appeal against his conviction. An Edinburgh court hears his health has deteriorated.
April 29, 2009: Prisoner transfer agreement between Britain and Libya comes into force, allowing al-Megrahi to apply to serve the rest of his sentence in a Libyan jail — if he drops his second appeal.
Aug. 14, 2009: Al-Megrahi applies to drop his second appeal.
Aug. 20, 2009: Scottish justice secretary Kenny MacAskill to announce decision in al-Megrahi case.