A British-born college teacher fatally injured after being shot in the head with an arrow by his own son has been hailed a hero after giving his students time to flee the classroom.
James Krumm, 56, was taking a computer science class at Casper College , in Casper, Wyoming, when his son Christopher barged in and shot him using a high-powered bow.
The 25-year-old had already stabbed to death his father's live-in girlfriend Heidi Arnold, 42, at their home two miles from the college.
As Mr Krumm fought with his son during the attack on Friday, the students in the classroom were able to escape to safety.
When police arrived at the World Physical Science Centre building, James Krumm was dead and his son was bleeding from self-inflicted knife wounds, Casper police chief Chris Walsh said.
He said: "I can tell you the courage that was demonstrated by Mr Krumm was absolutely without equal."
Authorities believe six students were in the classroom when the attack took place.
Mr Walsh said Christopher Krumm stabbed himself after shooting his father, then fatally stabbed his father in the chest during a struggle.
The son died shortly afterwards.
Ms Arnold, a maths teacher, died from multiple stab wounds and her body was found in the gutter near their home in Hawthorne Avenue.
He had smuggled the powerful compound bow on to the campus under a blanket, and was also carrying two knives.
Police carried out a search warrant at Christopher Krumm's last known address in Vernon, Connecticut, on Friday.
Andra Charter, a 20-year-old student, said she heard screams outside her biology class.
She said: "As we were walking out, there was a girl screaming 'there's somebody stabbing Mr Krumm!'"
James Krumm, who was born and grew up in the UK but is understood to have left the country by the time he was an adult, was head of the college's computer science department.
The college has planned a candlelight vigil and memorial service on Tuesday.