CASPER, Wyo. — Police released more details Saturday of a grisly murder-suicide at a Wyoming community college, saying a man shot his father in the head with a bow and arrow in front of a computer science class not long after fatally stabbing his father’s live-in girlfriend at their home a couple miles away.

Computer science instructor James Krumm, 56, may have saved some of his students’ lives Friday by giving them time to flee while trying to fend off his son, Christopher Krumm, 25, of Vernon, Conn., Casper Police Chief Chris Walsh said.

“I can tell you the courage that was demonstrated by Mr. Krumm was absolutely without equal,” he said, adding that his actions could offer some measure of comfort to those affected by the killings.

He said police still were trying to figure out what motivated Christopher Krumm to attack his father and girlfriend, 42-year-old Heidi Arnold, a math instructor at the college. Arnold was found stabbed to death in front of the home she shared with James Krumm.

After shooting his father with the arrow, Christopher Krumm stabbed himself, then fatally stabbed his father in the chest in a struggle in the classroom, Walsh said.

Police arrived to find James Krumm dead and Christopher Krumm barely living; the younger Krumm died soon after students fled in a panic. Authorities locked down the campus for two hours.

Reports began coming in about the attack on Arnold soon after the campus attack.

Christopher Krumm had smuggled the compound bow — a type much more powerful and effective for hunting than a simple, wooden bow — onto campus beneath a blanket, Walsh said.

He said Krumm also had two knives with him.