From www.nypost.com- Accused “Craigslist Killer” Philip Markoff had a fetish for women’s panties and collected underwear, which cops believe were “souvenirs” from his alleged victims, two law enforcement sources told ABC News.

The panties – found during a search of Markoff’s home – are one of the reasons authorities believe there could be more victims who have not yet come forward, the sources said.

The underwear was hidden in Markoff’s house and was marked and bagged by police as potential evidence in the case.

Prosecutor Dan Conley told ABC’s “Good Morning America” today that police are asking anyone who may have been contacted by Markoff on Craigslist to come forward – offering reassurance they would not be prosecuted for placing the ads.

“There could be none, there could be others,” he said. “We’re not interested in prosecuting them for massage services.”

Markoff, 23, is accused of robbing two women, whom he allegedly lured to upscale hotels through the Web site Craigslist, and killing one of them.

He pleaded not guilty on Tuesday.

Boston police have charged Markoff with the murder of 26-year-old Julissa Brisman, of Manhattan, at the Copley Marriott on April 14. She had placed an ad on Craigslist.

The other victim was robbed of $800, police said.

Police said they believe Markoff’s alleged crime spree was an effort to pay off his gambling debts.

Conley said Brisman was beaten very badly and shot three times at close range.

“This was a crime of great violence,” he said. “We felt it was a very dangerous man we were looking for.”

A wake for Brisman is scheduled for today in New York.

A source close to the investigation told ABC News that Markoff opened a line of credit at Connecticut’s Foxwoods Casino last year, possibly laying the framework for a crime spree to pay for his gambling habit.

Two days after Brisman was murdered, sources close to the investigation told ABC News that Markoff hit the casino again, leaving with $5,300 in his pocket.

Markoff liked to play blackjack and gambled with black $100 chips, the source said.

Markoff is also being looked at in a third attack, this one also a robbery, in a Rhode Island Holiday Inn where, again, a woman was tied up after placing an advertisement on Craigslist for massage services.

Prosecutors said Markoff was headed to the casino when they finally caught up with him Monday.

A search of his Quincy, Mass., apartment, they said, turned up a semi-automatic weapon along with ammunition, plastic zip ties and duct tape.

In his high-school yearbook, Markoff hinted at his passion, writing “I bequeath my poker playing skills” to a friend “so he won’t lose his dad’s house.”

Markoff and his bride-to-be – who met as undergrads at SUNY Albany, where they both worked as volunteers in a hospital emergency room – certainly appeared to enjoy the good life.

Their wedding site details an elaborate weekend shindig at a pricey Long Branch oceanfront restaurant, with entertainment by a Bruce Springsteen cover band, the B Street Band.

In online registries for their wedding, the couple hopes to score china by Kate Spade, Vera Wang stemware — and monogrammed martini glasses to match their pink dream kitchen. Markoff’s grandfather, Maryland lawyer Jerome Markoff, disputed the allegations, telling the Boston Globe, “This is not my grandson. “I know my grandson. I hate to see a rush to judgment.”