A number of ex-girlfriends of the alleged phony firefighter who sexually assaulted a Chelsea woman last week are calling the police to describe their dysfunctional relationships with the suspect, a police source told The New York Sun, but the women stopped short of claiming they were sexually assaulted by him.

While no sexual assault complaints involving the suspect, Peter Braunstein, 41, have been reported to police since the Halloween crime, the former head of the sex crimes unit in the Manhattan district attorney’s office, Linda Fairstein, said she suspects that two or three women will eventually come forward to divulge that he sexually assaulted them.

Mr. Braunstein was arrested in the spring and pleaded guilty in July to menacing his ex-girlfriend, a misdemeanor, and was sentenced to probation. He has not been arrested since then. Ms. Fairstein said it would be unusual that Mr. Braunstein would have moved from the lower-level crime of menacing to the “brazen” attack of last week, with no other crimes of escalating degrees in between.

Mr. Braunstein has been hiding out since police pointed to him as their only suspect in the Halloween incident when a man dressed as a firefighter allegedly started several blazes in a building and rapped on a 34-year-old woman’s door under the guise of helping her. Once she opened the door, he drugged and sexually assaulted her for about half a day in her West 24th Street apartment. The victim and the suspect both worked at Women’s Wear Daily, a Fairchild Publications magazine, at the same time, police said, although the woman did not appear to have known her attacker. Fairchild Publications declined to comment.

Police said this was the only case in recent history with this kind of modus operandi, but Ms. Fairstein recounted a case she prosecuted in which a doctor lured women to his apartment, drugged them, and sexually attacked them. That man is still on the lam, she said, having fled the country.

If Mr. Braunstein evades capture, Ms. Fairstein said, “I just don’t think he’d slip off into retirement and give up this kind of criminal behavior.”

Although it is not clear why Mr. Braunstein targeted the Chelsea resident, a forensic psychology professor at John Jay College of Criminal Justice and an expert in sexually motivated antisocial behavior, Louis Schlesinger, said that the attacker “may have had an obsessional attachment to her from a distance.” Very often, people with this trait switch the object of their affection, Mr. Schlesinger said, suggesting that the suspect could zero in on someone else and attack again.

Mr. Schlesinger described the suspect as intelligent and manipulative as evidenced by the sophisticated plan he executed in the Halloween attack. It is very possible, Mr. Schlesinger said, that the suspect could long elude police.

In the meantime, some women are worried about their safety. The assistant director of the Sexual Assault and Violence Intervention Program at Mount Sinai, Lynn Frederick-Hawley, said the recent crime, which has garnered major press attention, has elicited great fear in people. “This kind of case exposes all of our vulnerabilities,” she said. “We all think ‘I will do A, B, and C, and I won’t be raped.’…This is a case where everyone is saying ‘I would’ve done the same thing,’ so it concerns people.”