Casper police spokesman Justin Smith says authorities believe "around six" students were in the Casper College computer science class Friday morning when 25-year-old Christopher Krumm, of Vernon, Conn., entered and attacked his father, the instructor.

Casper Police Chief Chris Walsh says Christopher Krumm had first fatally stabbed his father's live-in girlfriend, 42-year-old Heidi Arnold, at the couple's home about two miles away.

Christopher Krumm then went to the college and shot his father, 56-year-old James Krumm, in the head with the high-powered bow and arrow before stabbing himself with a large knife.

Christopher Krumm was a graduate student at the Colorado School of Mines where he studied engineering.

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