A sex worker shared Stephen Paddock's "twisted" fantasies. It forms an unsettling pattern.

It has been eight days since Stephen Paddock, perched in his Las Vegas hotel room, unleashed the deadliest gun massacre in modern US history.

And still, the question ‘why?’ remains unanswered.

In our quest to make sense of the senseless, we find ourselves searching for as much information as we possibly can about the gunman, who ended his life without leaving so much as a whiff of the motive.

We know he was a 64-year-old, rich retiree from the small Nevada town of Mesquite. He lived with his Australian girlfriend Marilou Danley and frequented Las Vegas’ biggest casinos.

And up until the day he killed 58 innocents and injured hundreds – with a haul of weapons he amassed over a year – he was somebody with no known criminal history.

But now, a different side is emerging.

A sex worker has come forward to share her experience of Paddock, a man she described as “aggressive” and “obsessive”.

The 27-year-old woman told The Sun she saw him about nine times when he visited Sin City without Danley, and he paid her thousands of dollars to act out violent "rape fantasies".

"When he would have a winning streak (at the casino), we would go back and have really aggressive and violent sex," she said. "He had a dark and twisted side."

She also reportedly showed the publication threatening text messages he sent her, including ones where he wanted to see her "scream for help" and bragged about having "bad blood".

It is the first time Paddock has been described in any way as a violent person. In fact, his brother told The New York Times that not only was he "the most boring one in the family", he was also "the least violent".

But this should not be a surprise. Because time and again, the most savage of men have gotten away with walking freely among us.

Because instead of completely hiding their thirst for blood, they force a select few women to taste it. And nobody bats an eyelid until the violence escalates into something more deadly, more far-reaching.

Paddock's brutal treatment of sex workers falls into a familiar pattern, whereby perpetrators of mass killings first walked among us as perpetrators of violence against women.

LISTEN: Mia Freedman and Amelia Lester discuss the Las Vegas massacre. Post continues below.

Man Haron Monis, who plotted the Lindt Cafe siege in Sydney, had 43 sexual assault charges, and a history of domestic violence and harassment.

The man responsible for the Bastille Day attack in Nice last year, Mohamed Lahouaiej-Bouhlel had a long history of domestic violence.

The man who killed 49 people in a Orlando nightclub shooting, Omar Mateen, would often bash his wife when the laundry wasn’t finished on time.

Tamerlan Tsarnaev, one of the men behind the Boston Marathon bombings, was also known to police for domestic violence and beating women.

Paddock has not been accused of domestic abuse. So you might argue that this doesn't count, that the sex worker was paid to engage in vicious acts.

But regardless of the financial transaction, we are learning for the first time that there were clues this was a mind capable of unspeakable violence.

So perhaps it is time we stopped overlooking acts of violence against women, and time we took more seriously their link to mass killings.