Police release transcript of 911 calls from Pulse shooting

FORT MYERS, Fla. — For the first time, we can hear why Orlando shooter Omar Mateen why he carried out his attack.

Mateen, 29, walked into gay nightclub Pulse with an AR-15 and opened fire, killing 50 people. It is considered the worst mass shooting in U.S. history.

On Friday, police released a more comprehensive transcript of his conversations with hostage negotiators.

ISIS references were deleted from FBI transcripts to avoid giving the group a propaganda platform. Mateen said his attack was in retaliation for a U.S. airstrike in Syria a few weeks earlier.