Son of slain BYU professor Kay Mortensen has history of violent crime

PAYSON — A Payson man named as a "person of interest" in the slaying of his father has previously made violent threats against family members and others, court documents state.

Investigators say Roger Mortensen and his wife, Pamela, have made inconsistent statements about what happened Nov. 16, the night retired BYU professor Kay Mortensen, 70, was found with his throat slashed in a bathtub in his Payson Canyon home. Authorities have labeled both as persons of interest in the homicide case.

 On July 13, 1996, Roger Mortensen was driving down Mineral Basin Road in American Fork Canyon on a four-wheeler when he passed a car full of Boy Scouts, according to an affidavit filed in 4th District Court. For reasons that are unclear, Mortensen became "very upset," stopped and pulled out a handgun, the affidavit states.

He allegedly began yelling and pointed the gun at the driver's head. The driver continued down to a camp near Timpanogos Cave and reported the assault to authorities, who tracked down Mortensen and found him with the gun and a marijuana pipe, the affidavit states.

Mortensen was charged with aggravated assault, drug possession and receiving stolen property after detectives discovered he had a $4,000 radar unit belonging to the Utah Highway Patrol. A prosecutor stated in court papers that Mortensen was employed by UHP at the time, but the agency says it has no record of him working there.

Mortensen pleaded no contest to reduced charges of theft and exhibiting a dangerous weapon, and was given probation.

 When Mortensen was charged with theft in 1997 for allegedly helping his roommate steal dozens of tools from an Orem hardware store where Mortensen worked as a cashier, a jury found him guilty but mentally ill.

In a letter to the court, a therapist reported that due to a severe head injury Mortensen suffered in a fall off a cliff in 1994, his "daily functioning" was "extremely limited," and going to jail would hinder his treatment.

"He remembers how he used to be and has not yet accepted his limitations," the letter states.

The therapist also said that when Mortensen had previously been in jail, he was threatened and beaten by a group of inmates, and would later receive notices when one of the inmates who had gone to prison had a parole hearing.

"This terrifies Roger," the letter states. "He is afraid he will be killed if he goes to jail."