America is reeling from the worst mass shooting in its history after at least 50 people were killed and more than 200 wounded at a country music festival in Las Vegas on Sunday night.
Police say the shooter was 64-year-old Stephen Paddock, described as a local man, who opened fire on the Route 91 Harvest Festival from a room in the Mandalay Bay Hotel shortly after 10pm.
Officers say Paddock was shot and killed after they breached a room in the hotel, where he had stashed an 'arsenal' of weapons used during the massacre.
Investigators are now raiding the Mesquite home he shared with Marilou Danley, described as his 'companion', who was detained for questioning in the early hours of Monday morning.
Sheriff Joseph Lombardo, of the Las Vegas Metropolitan Police Department, said investigations are still ongoing and police have not yet determined a motive.
Terrifying footage from the scene shows concert-goers reacting with confusion and then panic as the festival turns into a bloodbath around them.
Video from close to the stage shows people hitting the floor as other crawl to safety or run for their lives. Audio from further back in the crowd captured several bursts of sustained automatic gunfire.
Witnesses said 'hundreds' of round of ammunition were emptied into the crowd, with Paddock stopping several times to reload as he carried out his massacre.
Among those shot dead at the concert were two off-duty police officers. Attendees said a large number of law enforcement and military personnel had been attending the show.
Two on-duty police officers who engaged the shooter have been hospitalized - one in critical condition, one less severely wounded. They have not been identified.