Las Vegas gunman 'would lie in bed moaning and screaming', girlfriend says

The Australian girlfriend of Las Vegas gunman Stephen Paddock said he showed signs of mental illness and would often lie in bed screaming.

Marilou Danley, 62, told FBI officials Paddock, the man behind the worst mass shooting in US history “would lie in bed, just moaning and screaming: ‘Oh my God’” NBC News reports.

Investigators are still trying to determine why the 64-year-old opened fire from a window at the Mandalay Bay hotel killing 58 people and leaving more than 500 injured.

The FBI is also investigating whether he planned a car bombing.

Stephen Paddock slaughtered 58 people using a stockpile of weapons. Source: PA via Yahoo UK

A former worker at the Atlantis Casino Resort and Spa in Reno, Nevada, where Paddock frequently gambled, said he had a “god complex” and always expected quick service.

“It was just his demeanour. It was like: ‘I’m here. Don’t cross me. Don’t look at me too long’,” said former executive host John Weinreich.

Police are also trying to determine if Paddock was working alone.

Las Vegas Sheriff Joseph Lombardo believes the 64-year-old had help in stocking up the 23 rifles and piles of ammunition in his room at the Mandalay Bay hotel, as well as the firearms and electronic devices found in his home in Mesquite, Nevada.

Police are now trying to identify a "mystery woman" seen with Paddock in the days before he carried out the massacre.

There is no evidence she was involved in the shooting, according to police officials, but officers would like to speak to her to establish a timeline of the killer’s movements in the days before the atrocity.

Lombardo told reporters: “Look at the weapon obtaining, the amounts of Tannerite available – do you think this was accomplished all on his own, face value?

“You gotta make the assumption he had to have help at some point, and we want to ensure that’s the answer.”

Ms Danley believes Paddock may have had mental illness. Source: 7 News

He added: “Put two and two together: another residence in Reno with several firearms, okay, electronics, and everything else associated with it, large amounts of ammo, a place in Mesquite.

“We know that he had a girlfriend. Do you think this is all self-facing, individuals are just, without talking to somebody, sequestered amongst themselves? Come on, folks.”