A 23-year-old Anne Arundel County man was identified in court papers yesterday as the attacker who pulled out a knife and fatally stabbed University of Maryland sophomore Brandon J. Malstrom early Sunday.

In documents charging Quan L. Davis of Hanover with first-degree murder, Prince George's County police allege that he killed Malstrom, 20, outside a white clapboard house in College Park where an off-campus student party was being held.

Witnesses at the party and co-defendant John Ryan Schlamp, who was charged with first-degree murder Sunday afternoon, told authorities that Davis "pulled an unknown object from his waistband, striking [Malstrom] in the torso," according to the court documents filed in Prince George's County.

Davis and Schlamp, 24, of Columbia, also punched and kicked at Malstrom, who attended the party with his older brother and several friends.

Police said yesterday they questioned a third man but concluded that he should not be charged.

Investigators say that Malstrom and his brother, Bill, a recent Salisbury (Md.) University graduate, were in the wrong place at the wrong time -- standing outside the house in the 7300 block of Dickenson Avenue when both suspects, allegedly seeking retaliation for being kicked out of the party they crashed, confronted them.

When Brandon Malstrom refused a demand that he hand over his cell phone, he was stabbed, police allege.

Schlamp was apprehended within minutes of the attack by a university police officer patrolling the area, but Davis was not arrested until Tuesday afternoon. Both are being held in the Prince George's County jail.

Neither suspect had an apparent connection to the university, and it was unclear how they knew each other. Police said Davis told them he had attended Oakland Mills High in Howard County and was an athlete at the school. Schlamp attended Howard High School, where he played varsity football.

The varsity basketball coach at Oakland Mills High said yesterday that a Quan Davis was a standout point guard and captain of his team before graduating in 1997. The documents filed by Prince George's police listed the suspect as 5-foot-3, a height that he said was consistent with the Quan Davis he coached.

The coach, David Appleby, said that "he kind of struck me as a guy who was his own man. He was kind of friendly with everybody, but not close to anybody." The player also excelled on the high school's football team and was a good student, said Appleby, who last spoke with the player about a year ago.

Schlamp appeared in Circuit Court yesterday before Judge Frank Kratovil, who ordered him held without bond. A bail hearing for Davis is scheduled for this afternoon.

During his brief court appearance, the 5-foot-3 Schlamp, a former high school football player, wore his ear-length blond hair slicked back and appeared disheveled. His attorney, Henry McRobie, said after the hearing that Schlamp was "obviously [at the party] and obviously involved, but how, exactly, we don't know at this point."

McRobie said he met briefly with his client and could offer scant details.

According to police and witness accounts, it was Schlamp who demanded that Malstrom hand over the cell phone. When Malstrom resisted, Schlamp shouted, "I'm going to kill you" and punched him, according to court documents.

Sheila Schlamp said yesterday that she last saw her son Friday afternoon. "I can't believe it. My son cannot be a part of this," she said.

But she acknowledged that he had been in trouble before. Court documents show that Schlamp was sentenced to a year's probation after pleading guilty to second-degree assault in a 1997 incident.

The documents say that Schlamp attended a party in Columbia thrown by the son of state Sen. Edward J. Kasemeyer (D-Baltimore County). The senator and his wife were not home at the time and the party apparently got out of control, prompting a noise complaint and police response. The assault charge accused Schlamp of kicking a police officer several times.

Court records also show that Schlamp was sentenced last year to three years' probation and fined $295 for driving under the influence of alcohol in May 2001. Conditions of the probation include staying away from alcohol.

McRobie, who also represented Schlamp in that case, said that "the reality of the [first-degree murder] charges have set in, and he's very, very upset."

It was only after Schlamp was arrested that another partygoer found Malstrom lying in the side yard of a nearby house, where he had apparently stumbled and collapsed.

Malstrom, a business major, was taken to Prince George's Hospital Center, where he died five hours later after undergoing surgery.

Staff writer Alicia Cypress and staff researcher Bobbye Pratt contributed to this report.