The FBI investigated the Orlando mass shooter for 10 months — and found nothing. Here's why
Omar Mateen pledged his allegiance to Islamic State before carrying out the massacre at an Orlando, Fla., nightclub, authorities say. (AFP/Getty Images) The veteran FBI agent and a local sheriff’s deputy took no chances when they got a credible tip about a potential terrorist. In a joint operation, they ran his name through a maze of federal criminal and terrorism databases and scrutinized his telephone records for suspicious contacts. Without a warrant, they couldn’t read his emails or listen to his calls.