The Sun reports Paddock boasted in text messages about his father Benjamin being a bank robber who escaped jail in 1969.
He wrote, 'I didn't have anything really to do with him but the bad streak is in my blood. I was born bad.'
The sex worker described the gunman as 'obsessive' and 'paranoid' and said he would rant about conspiracy theories, including claiming 9/11 was an inside job by the US government.
The escort, 27, saw Paddock, 64, around nine times from November 2015 to June 2016 when he would visit Las Vegas without his Australian girlfriend Marilou Danley. She also revealed he would pay her around $10,000 each time they met.
The woman, who has remained anonymous, said, 'When I first met Stephen I had left an abusive relationship and was starting all over again with nothing but the clothes I was wearing. He seemed like he wanted to help. We would go to casinos together and he would spend hours drinking and gambling.'
She continued, 'But when he would have a winning streak, we would go back and have really aggressive and violent sex.'
The Sun was shown text messages which appeared to show Paddock discussing tying her up 'as you scream for help.'
The escort broke off contact when she started a new relationship.
She said, 'He had a dark and twisted side. But even so, I could never have imagined he would do something like this.'
Police are still searching for Paddock's motive behind the mass shooting in Las Vegas just over a week ago.
This article originally appeared on New Idea.