WASHINGTON — Marilou Danley, the woman investigators hoped would provide key details into the motive behind her boyfriend's deadly shooting attack, said she remembers him exhibiting symptoms such as lying in bed and moaning, according to two former FBI officials who have been briefed on the matter.
"She said he would lie in bed, just moaning and screaming, 'Oh, my God,'" one of the former officials said.
The other former official said Danley spoke about Paddock displaying "mental health symptoms."
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But so far the FBI has not identified a clear motive, said two FBI officials. And they do not believe Paddock's mental health had deteriorated to a point that would have triggered him to commit such an act.
Paddock, however, had been prescribed the anti-anxiety medication Valium, state and federal law enforcement officials confirmed.
Other lines of inquiry the FBI and Las Vegas police are investigating include what Paddock did in the hour between shooting a security guard and his room being breached by officers. Paddock was found dead after a SWAT team breached his door, but it is unclear when he took his own life.
Investigators are also examining approximately 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.
Danley's lawyer did not immediately respond to a request for comment.
Julia Ainsley is a correspondent covering the Department of Homeland Security and the Department of Justice for the NBC News Investigative Unit.
Ken Dilanian is a correspondent covering intelligence and national security for the NBC News Investigative Unit.