DA investigating gambling as motive

BOSTON, Mass (WPRI) - Investigators in Boston are looking into gambling as a possible motive for suspected "Craigslist killer" Philip Markoff.

The 22-year-old Boston University medical student is accused of killing 26-year-old Julissa Brisman and robbing another woman at two Boston hotels. Markoff is also suspected of trying to rob a woman at a hotel in Warwick, but has not been charged.

Eyewitness News has learned Markoff may have built up a gambling debt, and investigators are looking into whether Markoff targeted women on Craigslist with intentions to rob them.

Investigators are unsure yet why Brisman was killed, but a clinical psychologist said money may not be the only motive.

"There's something that he is getting out of this that leads him to be compulsive, in the sense he is doing these crimes back to back," said clinical psychologist Matt Zaitchik.

Police arrested Markoff Monday while he was on his way to Foxwoods casino in Connecticut. He pleaded not guilty at his arraignment Tuesday, and is being held without bail.