From www.abcnews.com- Accused “Craigslist Killer” Philip Markoff will be hit with more charges today as Rhode Island prosecutors prepare to announce an arrest warrant for him for allegedly robbing an exotic dancer who advertised her services on the craigslist.org.

Rhode Island Attorney General Patrick Lynch will announce the charges at a 2 p.m. news conference. He will be joined by Warwick Police Chief Stephen McCartney.

The victim was allegedly restrained with plastic handcuffs and robbed at gunpoint at the Holiday Inn in Warwick, R.I., on April 16.

ABC News has learned that police tied Markoff to the hold-up through his fingerprints left at the hotel crime scene and by tracking phone calls and text messages Markoff allegedly made in the vicinity of the hotel around the time of the robbery.

Surveillance cameras also captured pictures of the suspect as he walked through the hotel lobby while staring at his cell phone.

Markoff already faces charges of robbing and killing masseuse Julissa Brisman, 25, in Boston on April 14, and robbing another woman in another Boston hotel. All three women advertised on Craigslist.

While officials most likely won’t prosecute him on the new charges until the more serious Boston cases are completed. The Rhode Island arrest warrant would preserve Rhode Island’s ability to try him at a later date.

The woman in the Rhode Island robbery has not been publicly identified, and police sources said she was reluctant to cooperate with investigators.

Nevertheless, evidence piled higher against Markoff as he sat in an isolated cell in a Boston jail. Markoff is being held in the jail’s psyche ward after two suicide attempts, sources have told ABC News. He isn’t scheduled to appear in court until May 21.

In the meantime, the only thing Markoff, a second year medical student who was engaged to be married, appears to have said to family members was to forget him. Fiancee Megan McAllister has told Markoff their August wedding is off, and she has moved her belongings out of the Boston apartment the couple shared.

Investigators found a pistol under the couple’s, bed along with women’s panties that police believe were taken from robbery victims. One of the alleged “Craigslist” victims, Trisha Leffler, said that after she was robbed, her assailant snatched a pair of her panties that were lying on the floor. A law enforcement source told ABC News that police found 16 pairs of women’s panties in the apartment, fueling concern that there might be other victims who have not yet come forward.

The gun was hidden in a hollowed each medical textbook entitled “Gray’s Anatomy,” sources said.

Also found in the couple’s apartment were plastic handcuffs identical to the ones allegedly used in the “Craigslist” robberies.