Police have identified Stephen Paddock as the suspected gunman in an attack at a Las Vegas music festival Sunday night that became the deadliest mass shooting in modern U.S. history.

The 64 year-old gunman opened fire on the outdoor Route 91 Harvest country music festival from his hotel room on the 32nd floor of the Mandalay Bay Resort and Casino, which sits at the southern end of the Las Vegas strip. The attack, which some witnesses told the Associated Press lasted around five minutes, killed at least 59 people and injured more than 500 others, according to police. SWAT teams found Paddock dead in the hotel room with at least 10 rifles.