BOSTON -- A former medical student bound, bludgeoned and shot a woman who advertised erotic services on Craigslist, and left her to die in a posh Boston hotel in April, Suffolk County prosecutors said Monday.

Philip Markoff, 23, accused of shooting 25-year-old Julissa Brisman, of New York, at the Boston Marriott Copley Place hotel on April 14, pleaded not guilty on Monday to seven charges including first-degree murder, kidnapping, armed robbery and weapons violations, handed up by a Suffolk County grand jury last week. Markoff is also accused in two other hotel robberies.

Officials believe that there was a brief struggle between Markoff and Brisman, a masseuse who advertised on the "exotic services" section of the Craigslist Web site, after they entered a room on the 20th floor of the hotel.

"Although there are no eyewitnesses to what happened inside the room, forensic analysis of the crime scene and results of the autopsy suggest that Brisman, after being bound with the same type of plastic ties that the defendant used (in a previous robbery), may have resisted," Assistant Suffolk District Attorney Edmond Zabin said. "The defendant, approximately 6 foot 2, and 200 pounds, attacks the woman, striking her in the head with severe force, causing trauma to her head, but not a life threatening injury. The defendant proceeded to take his gun, pointed it at Ms. Brisman at close range, fired three times striking her in the chest, upper torso and abdomen."

Zabin said Markoff then fled the hotel, leaving Brisman to die.

"Brisman was found by hotel guests at the threshold of her hotel room unresponsive. The three gunshots to her upper torso were the cause of death," Zabin said.

Zabin said Markoff's fingerprints were found on duct tape and plastic ties used to bind the victims.

Zabin said Markoff purchased the weapon, a 9 mm handgun, at Stateline Gun Shop in Mason, N.H., in February using another man's identity. Zabin said Markoff's fingerprints were found on the application to purchase the gun. The weapon was later found in a hollowed-out copy of Gray's Anatomy in the Quincy apartment Markoff shared with his former fiancee, Megan McAllister, Zabin said.

In a courtroom packed with the families of both Brisman and Markoff, the 23-year-old showed no emotion as he entered the not guilty pleas to all of the charges named in the indictment. He was ordered held without bail.

"Julissa inspired family and friends with her spirit and her dedication to helping others. We are very moved by the tremendous outpouring of support we received from those who lives she touched. Her loss to us is immeasurable and unfathomable. We ask for compassion and privacy as we continue the long process of grieving," Brisman family spokesman Jeremy Silverfine said.

Markoff's parents, brother and sister-in-law attended Monday's proceedings. They left the court without comment.

Markoff, a Boston University medical student, was also charged with robbery and kidnapping in connection with an attack on Trisha Leffler, 29, a Las Vegas prostitute, in Boston's Westin Hotel the week before Brisman died. Markoff is also suspected in an attempted robbery in Warwick, R.I., of a woman who had posted an ad as a stripper. All the women had advertised erotic services on Craigslist.

Prosecutors said Markoff used anonymous e-mail addresses and pre-paid cell phones to set up meetings with the women.

Prosecutors said that police allegedly found four pairs of women's underwear underneath Markoff’s bed at the Quincy apartment he shared with his fiancee. The underwear was bundled into socks and hidden in the box spring of the bed, according to police.

The parties will return to court Tuesday for a hearing about whether the grand jury was exposed to information from the media about the case, and if that played a role in the indictment.

"I'm starting this case at the very beginning, to look at these indictments and determine whether of not these proceeding were conducted appropriately or not appropriately," defense attorney Salsberg said.

The murder trial for Markoff is tentatively scheduled to begin on June 1, 2010.