Abu Agila Masud is said to have admitted his role to Libyan officials in 2012 The US on Monday unsealed criminal charges against Masud over the 1988 bombing of Pan Am Flight 103 over Lockerbie, Scotland, that killed 270 people Masud is said to have told investigators how he built the bomb used in the attack An FBI affidavit unsealed Monday says Masud told Libyan law enforcement that he flew to Malta to meet Abdel Baset Ali al-Megrahi and Lamen Khalifa Fhimah He then handed Fhimah a medium-sized Samsonite suitcase containing a bomb The suspected Lockerbie bombmaker is said to have told investigators how he avoided detection by airport scanners by positioning his explosive device near metal in a suitcase that was timed to go off 11 hours later.