Accused "Craigslist killer" Philip Markoff had scratches on his body when he was pulled over by police Monday, law enforcement sources told ABC News -- and his fingerprints were found on a plastic restraint used to bind a woman he's accused of murdering, sources said.
The information came to light as Markoff was put on a suicide watch after correction officers found shoelace marks on his neck, law enforcement sources said.
Markoff was arrested Monday and charged with the murder of Julissa Brisman, 26, a woman he contacted through a Craigslist ad offering exotic massage services.
He also is a suspect in the robberies of two other women who were contacted through Craigslist ads.
Ironically, Boston police now have placed an ad in Craigslist's "erotic services" section in an attempt to find additional victims, the Associated Press reported.
The posting does not mention Markoff by name.
Meanwhile, Markoff was moved from the general population of Boston's Nashua Street jail to a segregated unit where officers can keep a constant eye on him, sources said.
The move was made because "shoelace marks were found on his neck," law enforcement sources said.
Markoff's attorney, John Salsberg, visited the inmate today, but declined to discuss whether Markoff tried to commit suicide.
"I am deeply concerned for Philip's well being and I have complete faith that the sheriff's office will take care of him," Salsberg said.
He added that the transition for any individual from civilian life to prison life is extremely hard and Markoff's experience is no exception.
Police say Markoff killed Brisman last week in an upscale Boston hotel and robbed at least one other woman in Boston after binding her with plastic ties. The ties on Brisman had Markoff's fingerprints, sources said.
A police source close to the investigation told ABC News that officers recovered a semi-automatic handgun and panties belonging to Brisman in the Quincy, Mass., apartment Markoff shared with his fiancee, hidden in a copy of the popular medical school textbook "Gray's Anatomy."
And in Warwick, R.I., investigators said the plastic restraining ties used in an attack at a Holiday Inn Express -- on a woman who had advertised "erotic services" -- exactly match plastic ties found in Markoff's apartment.
In a twist, however, Warwick Police Chief Col. Steve McCartney told ABC News that the woman who was robbed in the Holiday Inn Express was reluctant to cooperate with the investigation.
The developments in the case were disclosed amid a report on Markoff's past interaction with a female friend.
Morgan Houston said she had a close call with Markoff, one of her study buddies when the two attended the State University of New York at Albany, after a night of partying four years ago.
"In a doorway, he pushed me up against the wall and tried kissing me," she said in a New York Daily News video. "I was trying to push him away, saying, 'No Phil, get off me.'"
Houston said she wasn't strong enough to push Markoff away, but that a mutual friend came to her aid.
"He had to physically pull him off me," Houston said.
Houston said it was the only time Markoff was aggressive toward her.
As news of the evidence trickles out, a profile is emerging of the man police believe attacked and robbed women he met through Craigslist to pay off his gambling debts.