Over the weekend, authorities identified the three people killed in last week's Wyoming murder-suicide.
Casper police say 25-year-old Christopher Krumm killed his father, James Krumm, just after stabbing his father's live-in girlfriend, 42-year-old Heidi Arnold.
James was a computer science instructor at Casper College; he was in the middle of teaching class to a handful of students when his son allegedly entered the classroom and shot his father in the head with a bow and arrow.
Police are giving James credit for trying to fend off his son, which gave students time to run.
"It wasn't long after that we received information that there were people being stabbed,” said Casper Police Chief Chris Walsh. “With that information, obviously we've got an evolving situation and reacted to it as we would an active shooter situation. Once that was issued every law enforcement officer in the county responded to that location."
After shooting his father with an arrow, Christopher stabbed himself, then proceeded to stab his father in the chest.
According to the Casper College website, James attended Colorado State University, where he earned a master's degree in computer science.