Evidence is mounting that Omar Mateen, the gunman who murdered 49 people in a gay nightclub in Orlando early Sunday morning, was himself gay. Mateen's horrifying attack on Pulse nightclub was initially thought to be a homophobic attack rooted in extremist Islamic ideology. But now his ex-wife and former security school classmate have stepped forward to say they think Mateen was gay, the same day it was revealed that Mateen had made at least a dozen previous visits to Pulse, and was a user of gay dating app Jack'd. Mateen's first wife, Sitora Yusufiy, whom he met online in 2009...