Las Vegas killer in his own words: 2013 deposition gives insight into Stephen Paddock's private life

Las Vegas killer Stephen Paddock, who opened fire on 22,00 concertgoers, killing at least 58 people, had a history of staying up gambling all night and sleeping  during the day.

A 2013 deposition detailed these sentiments and more, as part of a civil lawsuit filed against the Cosmopolitan Hotel, where Paddock slipped and fell in 2011.

CNN obtained the 97-page court deposition, which, the outlet said, was turned over to the FBI.

What did Paddock say about his anxiety and treatment?

According to Paddock, he suffered from anxiety and kept a doctor "on retainer" to address the issue. Paddock testified that the physician prescribed him Valium to alleviate symptoms of his condition.

"He's like on retainer, I call it, I guess," Paddock said of his Nevada-based doctor. "It means I pay a fee yearly. ... I have good access to him."

Paddock's fixation on gambling and how it affected his sleep cycle

Paddock's testimony included various bits about his gambling habits.

At one point in the deposition, Paddock described himself as the "biggest video poker player in the world."

"How do I know that?" he asked. "Because I know some of the video poker players that play big. Nobody played as much and as long as I did."

Paddock testified that in 2006 — the pinnacle of his playing — he averaged "14 hours a day, 365 days a year."

"I'll gamble all night," Paddock said. "I sleep during the day."

When asked if he visited the hotel pool at the Cosmopolitan Hotel, Paddock answered, "I do not do sun."

He also stated that he didn't drink much alcohol when he gambled in order to stay focused.

"At the stakes I play, you want to have all your wits about you, or as much wit as I have," he said, in the deposition.

Paddock's demeanor described

CNN reported that the transcript of Paddock's deposition suggested that his demeanor was "arrogant and sarcastic" at times throughout his interview.

When the lawyer asked Paddock about his gambling habits and how much money he would sometimes bet in a night, Paddock answered "a million dollars."

"That's a lot of money," the lawyer said.

Paddock answered: "No, it's not."