After F.B.I.’s Inquiry into Omar Mateen, a Focus on What Else Could Be Done

{snip}

The nightclub shooting in Orlando, Fla., in which a gunman killed 49 people, has brought unusual attention to a seemingly mundane process. For 10 months, F.B.I. agents investigated the gunman, Omar Mateen, but closed the investigation after following a standard checklist. F.B.I. supervisors approved the decision. Managers in Washington, who can reverse any decision to close a case, were notified.

{snip}

{snip} Tens of thousands of counterterrorism tips flow to the F.B.I. each year. Some are legitimate. Others come from vengeful ex-spouses or people casting suspicion on Arab-Americans.

Thousands of investigations are opened and closed. Right now, law enforcement officials say, the F.B.I. is investigating 1,000 potential “homegrown violent extremists,” the majority of whom are most likely tied to or inspired by the Islamic State. Fifty to 100 are considered the highest priority.

{snip}

In Mr. Mateen’s case, co-workers said in 2013 that he had boasted of ties to the terrorist groups Hezbollah and Al Qaeda. The remarks prompted the local sheriff to request his removal from the St. Lucie County Courthouse in Fort Pierce, Fla., where he worked as a security guard. The security contractor transferred him to work at a residential golfing community, and the sheriff alerted the F.B.I.

Government officials said his claim had been dubious from the beginning. Hezbollah is a Shiite group; Al Qaeda is Sunni. But agents opened what is known as a preliminary investigation. They secretly followed him and monitored his movements. They interviewed him twice, and dispatched an informant to get close to him in an investigation that spanned nearly a year.

{snip}

As the F.B.I. pieces together details of Mr. Mateen’s life, lawmakers and lobbyists are already questioning whether the authorities missed any leads. Senator Charles E. Grassley, Republican of Iowa and chairman of the Judiciary Committee, sent a letter to Obama administration officials demanding information about Mr. Mateen, his family and the dates he was on a terrorism watch list.

James B. Comey, the F.B.I. director, has said Mr. Mateen was on a watch list during his investigation. Once it was closed, he was removed from the list, as is required. “We don’t keep people under investigation indefinitely,” he said.

Even if Mr. Mateen had remained on the watch list, it would not have stopped him from buying a gun. Congress blocked an attempt last year to give the F.B.I. the power to block gun sales to people on terrorism watch lists.

{snip}