AMERICAN FORK — A 3 1/2 mile police chase that ended in the death of an 88-year-old man began with a traffic stop for a revoked registration, American Fork police said Monday.

It continued because the 21-year-old driver, Trevor Pitcher, "was scared based on his past experience with law enforcement" and did not want his pickup truck impounded, according to a probable cause statement. Pitcher also said he thought officers would eventually stop pursuing him.

<strong>There&#39;s so many things that they have to weigh in their mind.</strong> – Sgt. Josh Christensen on the factors officers consider in determining whether to initiate a chase

The truck ran a red light, crashing into the passenger seat of a car at 900 W. State and killing Hal Gadd, of American Fork, Sgt. Josh Christensen said Monday. Gadd's wife, whose name was not released, sustained serious internal injuries and remained in the hospital. Officers initially believed she had only minor injuries.

A Utah County sheriff's deputy made a traffic stop at 500 E. State on Friday when he learned the truck had its registration revoked and did not have insurance, Christensen said. His agency is handling the criminal investigation, he said. The Utah County Attorney's Office is reviewing the officer's conduct.

The chase went onto I-15, then onto Main Street in Lehi and east back to American Fork, where the fatal crash occurred, according to the probable cause statement.

Christensen said officers consider traffic, road conditions and other factors in determining whether to initiate a chase.

"There's so many things that they have to weigh in their mind," he said. He did not release the name of the sheriff's deputy.

It's not clear how much discretion the Utah County Sheriff's Office permits officers initiating chases. A heavily redacted copy of the office pursuit policy provided to the Deseret News states that "Pursuit driving is necessitated by the suspect's disregard for the law and the safety of others, and the responsibility charged to law enforcement officers to help apprehend such persons."

Pitcher, from West Jordan, was treated at a hospital for minor injuries and booked into Utah County Jail on investigation of manslaughter, evading police, reckless endangerment and red light violation, police said. He has not been formally charged in the case.

Court records show in 2016 he pleaded guilty to failure to stop or respond at command of police, a class A misdemeanor, and reckless driving, a class B misdemeanor. There was no warrant for his arrest at the time of the crash.

Initial toxicology tests showed that impairment was not a factor, but police were awaiting further results, Christensen said.

Christensen said officers' hearts go out to Gadd's family as they grieve and support his wife's recovery. His funeral is scheduled for Thursday in American Fork.

American Fork police are asking anyone who may have video footage of the pursuit or crash to call them at 801-763-3020