Here's an in-depth look at the life of Khalid Sheikh Mohammed.
Birth date: March 1, 1964 or April 14, 1965 (both are used)
Birth place: Kuwait
Father: Sheikh Mohammed Ali Doustin Baluchi
Mother: Halema Mohammed
Marriage: Wife's name unavailable publicly
Children: Abed al-Khalid; Yusuf al-Khalid
Education: North Carolina A&T University, Mechanical Engineering, 1986
Has been called "the mastermind of the September 11th attacks."
Has been linked to nearly every al Qaeda attack between 1993 and 2003.
Is sometimes referred to as KSM.
January 1995 - Mohammed first comes to the attention of the FBI and CIA because of his involvement in a failed plot to blow up as many as a dozen American commercial airliners over the Pacific. After a fire in the apartment in Manila, Philippines, where the planning took place, the Manila police discover a computer where the plans were laid out and arrest some of the conspirators.
1995 - Mohammed is linked to a plot to assassinate Pope John Paul II during his visit to Manila, Philippines.
1996 - Is indicted on seven counts of terror conspiracy in the Southern District of New York for his alleged involvement in a Philippines-based plot to blow up 12 U.S.-bound commercial airliners in 48 hours. Referred to as the "Bojinka Plot."
1998 - Is linked to bombings of U.S. Embassies in Kenya and Tanzania.
October 2000 - Is linked to the bombing of the USS Cole.
September 11, 2001 - Is linked to the terrorist attacks on the World Trade Center and Pentagon.
2001 - Is linked to Richard Reid's foiled attempt to blow up an airliner with a shoe bomb.
October 2001 - Placed on the FBI list of 22 Most Wanted Terrorists.
2002 - Al Qaeda expert Rohan Gunaratna says Mohammed ordered the killing of Wall Street Journal reporter Daniel Pearl saying "Daniel Pearl was going in search of the al Qaeda network that was operational in Karachi, and it was at the instruction of Khalid Sheikh Mohammed that Daniel Pearl was killed."
October 2002 - Is linked to the Bali nightclub bombing that killed more than 200 people.
November 2002 - Is linked to the bombings at the El Ghriba synagogue, in Djerba, Tunisia.
March 1, 2003 - Mohammed is captured in a house in Rawalpindi, Pakistan, along with Pakistani political leader Ahmed Abdul Qadoos, Mustafa Ahmed al-Hisawi (another alleged al Qaeda operative), and Jamaat Islami.
September 6, 2006 - The United States acknowledges Mohammed has been held at a secret overseas CIA prison and is being transferred to Guantanamo Bay, Cuba where he will face a trial before a military commission.
March 15, 2007 - In a 26-page transcript released by the Pentagon, Mohammed admits decapitating Daniel Pearl and responsibility for the Richard Reid shoe bomber attempt to blow up an airliner over the Atlantic Ocean, the Bali nightclub bombing in Indonesia, the 1993 World Trade Center attack and other attacks that did not play out. "I was responsible for the 9/11 operation, from A to Z."
February 11, 2008 - The United States announces it will seek the death penalty against Mohammad, along with Mohammed al-Qahtani, Ramzi bin al-Shibh, Ali Abd al-Aziz Ali, Mustafa Ahmed al-Hawsawi, Walid bin Attash, and Mohammed bin Attash, for charges related to the 9/11 attacks which include: conspiracy, murder in violation of the law of war, attacking civilians, attacking civilian objects, intentionally causing serious bodily injury, destruction of property in violation of the law of war, and terrorism and material support of terrorism.
June 5, 2008 - The arraignment for Khalid Sheikh Mohammed and four co-defendants begins. Mohammed tells the judge, Marine Colonel Ralph Kohlmann, that he wishes to represent himself, understands the charges against him could lead to the death penalty, and wishes to plead guilty to all charges in connection with his role in the 9/11 attacks and become a martyr.
January 19, 2009 - Mohammed and Ramzi Binalshibh admit in open that they are guilty and proud of the attacks committed on September 11.
January 21, 2009 - At the request of President Obama, trial proceedings are frozen for 120 days.
April 16, 2009 - The U.S. Justice Department releases a 2005 memo which states that Mohammed was waterboarded 183 times in March 2003.
September 21, 2009 - The government's request for a 60-day delay in the trial is granted. Decisions on where to try the case are being worked out.
November 13, 2009 - The Justice Department announces five Guantanamo Bay detainees, including Mohammed, will be transferred to New York for trial in a U.S. District Court courtroom just blocks from the site where the World Trade Center twin towers stood until September 11, 2001.
May 31, 2011 - The Department of Defense announces that capital charges have been re-filed against Mohammed and four other alleged 9/11 co-conspirators. The charges include: conspiracy, murder in violation of the law of war, attacking civilians, attacking civilian objects, intentionally causing serious bodily injury, destruction of property in violation of the law of war, hijacking aircraft and terrorism. He will be tried before a military commission at Guantanamo Bay, Cuba.
April 4, 2012 - Vice Admiral Bruce MacDonald authorizes a new trial for Mohammed and the four co-conspirators.
May 5, 2012 - Is arraigned at Guantanamo Bay along with Walid Muhammad Salih Mubarak Bin 'Attash, Ramzi Binalshibh, Ali Abdul Aziz Ali, and Mustafa Ahmed Adam al Hawsawi. The five refused to co-operate with court proceedings in various ways. They are each charged with terrorism, hijacking aircraft, conspiracy, murder in violation of the law of war, attacking civilians, attacking civilian objects, intentionally causing serious bodily injury and destruction of property in violation of the law of war. The hearing lasts 13 hours and is the first time the defendants are seen in public since January 2009.
October 17, 2012 - At a pretrial hearing at Guantanamo Bay, Mohammed declares that the U.S. government sanctioned torture in the name of national security and equates the plane hijackings that killed nearly 3,000 people to the "millions" he said have been killed by America's military. After Mohammed's remarks, military judge Captain James Pohl says that no other personal comments by the accused will be allowed.
January 28, 2013 - The second session of the pretrial motion hearing against Mohammed takes place at Guantanamo Bay.
March 18, 2014 - A federal judge denies a request by Sulaiman Abu Ghaith, Osama bin Laden's son-in-law, to have Mohammed testify in Abu Ghaith's defense at trial, either by teleconference from the Guantanamo Bay detention camp or via deposition.
December 9, 2014 - The Senate Intelligence Committee releases its report on "enhanced interrogation techniques" used by the CIA in the post-9/11 era. Mohammed was waterboarded at least 183 times. The CIA said the method was effective in helping CIA interrogators pull information from Mohammed, but according to the Senate report, Mohammed figured out a way to "beat the system," often recanting information he told CIA officers to get them to stop the waterboarding.