FBI had closely scrutinized the Orlando shooter before dropping investigation | 13 June 2016 | The FBI investigated the Orlando shooter for 10 months beginning in 2013, putting him under surveillance, recording his calls and using confidential informants to gauge whether he had been radicalized after the suspect talked at work about his connections with al-Qaeda and dying as a martyr. As part of the investigation, Omar Mateen, who was killed in a shootout with police on Sunday morning, was placed on a terrorism watch list and interviewed twice before the probe was closed in March 2014 because agents concluded he was not a threat, FBI Director James B. Comey said Monday in an interview with reporters at bureau headquarters. Several months later, in July 2014, Mateen surfaced in another investigation into the first American to die as a suicide bomber in Syria, a fellow Floridian. And, again, investigators moved on. It was the third time -- following the Boston Marathon bombing in 2013 and a planned attack last year on a contest to draw the prophet Muhammad -- that someone who had been scrutinized by the FBI later carried out a terrorist attack.