Boston University graduate student Philip H. Markoff appears at Boston Municipal Court for his arraignment on April 21, 2009. Markoff, who has been dubbed the "Craigslist killer," was charged with the murder of masseuse Julissa Brisman, who he allegedly lured to his hotel room through an ad posted on Craigslist. (UPI Photo/mark Garfinkel/Pool) | License Photo

BOSTON, April 22 (UPI) -- Police searching the Quincy, Mass., apartment of accused Craigslist killer Philip Markoff say they found undergarments belonging to two of the victims.

A law enforcement official, who spoke on condition of anonymity, told The Boston Globe the women's underpants and a handgun were found hidden in a hollowed-out copy of Gray's Anatomy of the Human Body, a medical textbook.


Authorities have said Markoff, a student at Boston University School of Medicine, may have been motivated to commit the crimes because of a gambling problem.

Markoff, 23, pleaded not guilty Tuesday to charges involving attacks on two women he met through Craigslist at Boston hotels and police said a prostitute, who also advertised on the Internet Web site, was attacked at a hotel in Warwick, R.I.

Police were conducting forensics to determine whether the semi-automatic handgun found in his apartment was the same weapon used to kill a 26-year-old Boston masseuse and aspiring model.

"He chose women, and he chose women who were living somewhat on life's margins, so that he could dominate them, abuse them," said Suffolk District Attorney Daniel F. Conley. "He seems to have no problem physically hurting women and dominating them."

Markoff's attorney, John Salsberg, insists his client is innocent and is not the so-called "Craigslist killer."