Federal prosecutors and attorneys for a former state trooper battled Thursday over his state of mind at the time he kidnapped a trucker while on duty in January.

The outcome could affect the length of Franklin Ryle Jr.’s prison sentence. His attorneys are expected to argue their client suffered from reduced mental capacity at the time, and therefore qualifies for a lighter sentence.

Ryle’s sentencing hearing in U.S. District Court in Cheyenne focused mainly on his mental state. After five hours of testimony, Judge Alan Johnson stopped the proceedings for the night. They are scheduled to resume today.

A psychiatric expert called by the defense testified Ryle’s power of reason was impaired during the crimes. As evidence, he pointed to the former trooper’s bizarre scheme to kill the Wal-Mart trucker and stage a crash in order to collect settlement money from the company.

“The plan, as it was detailed, had zero chance for success,” Dr. Bruce Kahn told the court.

A forensic psychologist called by prosecution disagreed with that assessment, noting how Ryle built his plan up over time and tried to enlist help from friends.

“He used [his reason] before, during and after the commission of the crime,” the psychologist, Chuck Denison, testified.

Ryle, 42, pleaded guilty in July to violating the trucker’s civil rights and carrying a gun during the Jan. 8 crime. He stopped and arrested the truck driver near Douglas, but released him about an hour later after explaining he’d made a mistake.

Federal sentencing guidelines call for a 19- to 22-year sentence for Ryle.