Las Vegas police and federal agents are beginning to piece together information about 64-year-old Stephen Craig Paddock, the suspected gunman behind the mass shooting at the Route 91 Harvest country music festival Sunday night.

The Las Vegas Metropolitan Police Department said Paddock, a white male from Mesquite, Nev., opened fire on a crowd of more than 22,000 people from his hotel room on the 32nd floor of the Mandalay Bay Hotel at 10:08 p.m. Sunday.