Police arrested a University of Maryland student Wednesday, claiming the man intentionally set a fire that killed a fellow student because he was upset about being teased.

Daniel Murray, 20, was charged with murder and arson in the April 30, 2005, fire, Prince George's County police said.

According to court papers, a break in the yearlong investigation came last week when an anonymous tipster contacted police with information that led to an interview with Murray's co-worker.

The co-worker told police Murray had been angry about something that happened at the house a few hours before the fire, then returned with a can of gasoline and intentionally started the blaze.

"He started getting teased and a little altercation ensued," Lt. Robert Nealon said Thursday at a news conference. Nealon said Murray, of Berwyn Heights, had confessed to starting the fire and was cooperating with authorities.

It was not clear Thursday if Murray had a lawyer who could comment. He was being held pending a Friday court appearance.

The fire killed Michael A. Scrocca, a 22-year-old finance major from Branchburg, N.J. Firefighters found Scrocca in a second-floor bedroom and a gasoline can on the porch. Another man in the home was seriously burned but survived after jumping from a second-floor window.

Seven students were renting the 2 1/2-story house and had hosted a party that ended a few hours before the fire broke out. According to investigators, about three dozen people attended the party.

Steve Kerpelman, a private investigator working for the Scrocca family, said he conducted more than 100 interviews, but never determined whether Murray was ever in the house.

"Nobody knew him," Kerpelman said. "He wasn't associated with the house at all."

Kerpelman said witnesses denied that there had been any serious dispute at the party, although someone had apparently shouted at a departing guest to close the door. Police said someone in the house apparently shouted at Murray as he walked by.