Courtesy of Casper College James Krumm, 56, and Heidi Arnold, 42, were stabbed to death on Friday by Krumm's 25-year-old son, Christopher Krumm.

Police say a Wyoming community college teacher James Krumm was a hero for fighting off his son on Friday, potentially saving the lives of six of his computer science students.

"I can tell you the courage that was demonstrated by Mr. Krumm was absolutely without equal," Casper Police Chief Chris Walsh said, according to The Associated Press.

On Friday, Christopher Krumm, 25, stabbed his father’s girlfriend to death before driving to Casper College, where his father was teaching a class. He was equipped with a compound bow and arrow and two knives, which he carried into the building under a blanket.

When he entered the classroom, Christopher Krumm stood about four feet from his father, pulled back the bowstring and shot an arrow through his father’s head, the Casper Tribune reported.

His father, James Krumm, 56, fell but got back up and struggled with his son, the Tribune reported.

That’s when Christopher Krumm stabbed himself, then plunged the knife into his father’s chest, killing him, Walsh said.

When police arrived, the elder Krumm had died and the younger was taking his final breaths.

Back at his home, girlfriend Heidi Arnold’s body lay in front of the house for 11 hours, neighbor Heather Meier told the Tribune. Arnold, 42, was barefoot and her midriff was visible, Meier said. Authorities didn’t cover her body.

"I can’t keep it out of my head," Meier told the Tribune.

Police believe that Christopher Krumm drove from Vernon, Conn., where he was living, and booked into a motel on the outskirts of town on Thursday, the day before the killings.

Matt DiPinto, a neighbor in his apartment building in Vernon, described an interaction he had with Krumm to the Hartford Courant newspaper. Krumm was giving him a ride back from McDonald’s.

"He told me his dad gave him Asperger's (syndrome), that his dad shouldn't have passed it on," DiPinto said. "He said his dad should be castrated. I didn't know him that well, he just kind of said it out of nowhere, so that kind of threw me off a little."

Related: Asperger's disorder being dropped from psychiatrists' diagnostic manual

On the Casper College website, James Krumm described himself as a teacher born in London, England and partly raised in Germany. He started teaching at Casper College in 2002.

The Associated Press contributed to this report

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