A police investigator says no one seems to know why a teenage student at Montana State University knocked on a door in Langford Hall and then opened fire with a snub-nosed automatic shotgun, killing the student who opened the door and a second student inside the room.

The assailant apparently didn't know either of the freshmen victims, officials said.The dual slaying sent shock waves through the Bozeman campus Tuesday. School officials said there never before had been a homicide on campus in MSU's 97-year history.

A memorial service was scheduled for the two dead students Wednesday, and schoolmates were told they would be excused from classes to attend.

Police Col. Dick Boyer said both victims were shot multiple times with a 12-gauge sawed-off shotgun that had a pistol grip in place of a normal stock.

He said police had no motive. "This is real hard," he said, calling the incident a tragedy unlike anything else he has seen in 20 years on the force.

Brett Byers, a 19-year-old sophomore majoring in business management, was arrested a few hours after the shooting spree about 90 miles from the campus, near Helena. A high-speed chase that began when his vehicle was approaching East Helena ended a short time later when the pickup truck crashed at a convenience market, striking a power pole and knocking out a gasoline pump before smashing into a Jeep parked nearby.

Byers was not seriously hurt. He said nothing when he appeared in justice court at Helena on two counts of deliberate homicide, felony criminal mischief and reckless driving. Later, in Bozeman, a justice of the peace ordered him to appear back in court May 30 for a preliminary hearing.

He was ordered held without bond.

It was about 2:20 a.m. Tuesday when the quiet of Langford Hall was shattered.

"I thought I heard arguing, and then it sounded like glass breaking," said Tim Stoppa, one of the stunned dormitory residents. "It didn't sound like shots, and I just thought someone was screwing around."

He said when he looked into the hall there was blood all over.

Another student, who asked not to be identified, said the gunman ran down the hallway screaming, "Call the police, there's been murder," and left the building.

James Clevenger, 19, of Billings, stumbled down the hallway before collapsing. The legs of Brian Boeder, also 19 and from Plymouth, Minn., were sticking out of the room. Both men were bleeding profusely. Both died before dawn in a hospital.

Witnesses said the victims talked to each other as they were being treated in the dorm and placed on stretchers. They said Boeder asked Clevenger if he was going to make it and the reply was, "Not this time."

Shaken students and officials at the dormitory said they did not know what might have provoked the shootings.

James Hesterberg, another dorm resident, said he and Byers had played video games in his room until after 1 a.m. He said Byers had been drinking and had a bottle of wine with him when he arrived.

Students alternately described Byers as someone who was quiet or oddly talkative.

"He talked too much, maybe," said Scott Adams, a dormitory resident. "He was kind of different. He didn't have many friends."

Byers' parents are civic leaders in Great Falls. His father, Don Byers, is executive director of Montana Special Olympics and his mother, Lila Byers, is a third-grade teacher and incoming president of the local Junior League.