The deadliest mass shooting in modern American history killed 49 people after a gunman attacked a gay dance club in Orlando, Florida. Omar Mateen, of Port St. Lucie, Florida, shot his way into Pulse nightclub at 2 a.m. Sunday with an assault rifle, Orlando Police announced Sunday. Mateen reportedly took hostage several patrons who were hiding in a bathroom. A SWAT unit entered the club at 6 a.m. and killed Mateen in what was described by law enforcement as a sustained gun battle. Mateen used an “AR-15-style assault rifle,” Orlando Police Chief John Mina said. The AR-15 has been the signature weapon of mass shooters in America, used by Adam Lanza to kill 26 at Sandy Hook and the San Bernardino terrorists to kill 14