Vegas Shooter's Girlfriend Recalls He Would Lie in Bed 'Moaning, Screaming'

Marilou Danley, the woman the FBI hoped would provide key details into why her boyfriend, Stephen Paddock, carried out Sunday's mass shooting in Las Vegas, said Paddock exhibited symptoms like lying in bed and moaning, according to NBC News.

"She said he would lie in bed, just moaning and screaming, 'Oh, my God,'" a former FBI official who had been briefed on the investigation said.

Another former FBI official said that during her four-hour interview with the FBI on Wednesday, Danley spoke about Paddock displaying "mental health symptoms."

Investigators now think that Paddock could have been in mental or physical anguish at the time of the domestic terror attack, but they do not believe his mental health would have deteriorated to such a state that would have triggered him to kill 58 people and injure hundreds more, as he did at the Route 91 Harvest Festival.

State and federal law enforcement officials did confirm that Paddock had been prescribed the anti-anxiety medication Valium.

Officials are also reportedly examining six media devices left behind by Paddock, one of the former officials said.

Included in that search is an inquiry into Paddock's web browsing history. Multiple law enforcement officials told NBC News that Paddock researched other attack locations in Boston and Chicago.

Clark County Sheriff Joe Lombardo says that police have evidence supporting the theory that Paddock planned to escape the hotel alive and that he may have even had potential accomplices.

"What we know is that Stephen Paddock is a man who spent decades acquiring weapons and ammo and living a secret life," Lombardo said.