( CNN ) -- A 22-year-old college student in Boston , Massachusetts , has been charged with murder in connection with the death of a woman who may have been contacted through a Craigslist ad , police said . Police found Julissa Brisman , 26 , unconscious with multiple gunshot wounds on April 14 . She later died . Philip Markoff , a pre-med student at Boston University with no criminal record , also was charged with the armed robbery and kidnapping of another victim , Police Commissioner Ed Davis announced Monday evening . Markoff , who was under police surveillance , was arrested earlier in the afternoon after a traffic stop south of the city , police said . Markoff is suspected in the death of New York City resident Julissa Brisman , 26 , who was found unconscious with multiple gunshot wounds at Boston 's Copley Marriott Hotel on April 14 . She was transferred to Boston Medical Center , where she died from her injuries shortly afterward . Police said that Brisman , a model , offered massages via Craigslist , a popular online classified ads service . The confrontation between Brisman and her killer seems to have begun as an attempted robbery , police said . `` It appears that there was a struggle between the victim and the suspect in the threshold of the hotel room immediately prior to the shooting , '' the Boston Police Department said in a statement posted on its Web site . Surveillance videos from the hotel where Brisman was murdered showed a tall , clean-cut young blonde man in a black windbreaker leaving the property , said the Boston Police Department , which had asked for the public 's help in identifying the man . Police did not release a photo of Markoff on Monday . Four days before Brisman 's killing , Markoff allegedly robbed a 29-year-old woman at gunpoint at a Westin Hotel in Boston , Suffolk County District Attorney Dan Conley said . A police spokesman would not disclose the details of her Craigslist ad but said she and Brisman were `` involved in similar professions . '' `` This is a compelling case with a myriad of evidence -- with computer evidence being a part of it , '' Conley said , adding that additional search warrants would be executed this week . Markoff 's arraignment was set for Tuesday morning at the Boston Municipal Court . It was not immediately clear if he had retained defense counsel . Davis and Conley warned there may be other victims that come forward in the case . `` We would like to make one final pitch to those out there who may have been a victim of robbery at the hands of Philip Markoff , especially those who may have used Craigslist in the manner in which the victim used Craigslist , '' he said . Authorities received more than 150 leads in the case , which Davis credited to the popularity of the Web site . `` The public came forth , they were fascinated by this crime , '' he said , adding , `` I wish we had this level of cooperation in every homicide that occurred . '' Davis said Boston investigators were working with police in Warwick , Rhode Island , in what could be a related case . On April 16 at a Holiday Inn Express in Warwick , Rhode Island , a man tied up and demanded money from a 26-year-old dancer who had posted a Craigslist advertisement , according to Warwick Police Chief Col. Stephen McCartney . The robbery was interrupted when the woman 's husband entered the room . After pointing his gun at the husband , the suspect fled , according to McCartney . He said no conclusions could be made , but allowed that the incident `` may be related to similar crimes occurring in the Boston area . '' Watch police say assailant is perusing Craigslist ads » . Craigslist CEO Jim Buckmaster said the company was `` horrified and deeply saddened that our community services have been associated in any way whatsoever with a crime of violence . '' He promised that Craigslist would evaluate the incident to see if additional measures could be introduced to further protect users . CNN 's Jason Kessler contributed to this report .
NEW : Police make public plea to `` those who may have been a victim '' on site . The man was found dead in the back of his car at about 10.30am yesterday morning. Suspect also charged in kidnapping , armed robbery of another victim . Woman found with gunshot wounds was model who advertised on Craigslist .