WASHBURN, N.D. (AP) — The adult son of U.S. Sen. Kevin Cramer pleaded not guilty Wednesday to homicide and other charges in connection with a Dec. 6 crash that killed a North Dakota sheriff's deputy.

Ian Cramer, 43, waived his preliminary hearing and entered his not guilty plea to felony charges of homicide while fleeing a peace officer, preventing arrest, reckless endangerment and fleeing an officer, as well as three misdemeanor drug charges and other low-level offenses of driving under suspension and marijuana possession.

A jury trial is scheduled for July. Cramer was initially charged with manslaughter, which was subsequently upgraded to the homicide count.

Ian Cramer's court appearance lasted just a few minutes. He answered yes and no to procedural questions from state District Judge Bobbi Weiler. He briefly conferred with his public defender outside the courtroom after the hearing, then entered an elevator with two sheriff's deputies.

Bismarck police said Ian Cramer's mother had taken him to a hospital because of mental health concerns. Court documents say he crawled into the driver seat of his parents' vehicle after his mother got out and smashed in reverse through the closed garage door of the hospital's ambulance bay. Court documents say he later fled from deputies when one confronted him in Hazen, about 70 miles (113 kilometers) from Bismarck.

Cramer hit speeds over 100 mph (160 kph) and kept going even after a spiked device flattened two tires, according to court documents. More spikes were set up and Cramer swerved and then crashed head-on into Mercer County Sheriff's Deputy Paul Martin’s patrol vehicle and launched him about 100 feet (30 meters), authorities said. Martin, 53, was pronounced dead at a local hospital.

In March, Ian Cramer pleaded not guilty to separate felony charges of theft, criminal mischief and reckless endangerment in connection with the events at the hospital. A jury trial is scheduled for June.

Sen. Cramer has said his son “suffers from serious mental disorders which manifest in severe paranoia and hallucinations.”

Cramer was scheduled for a criminal responsibility evaluation in March at the State Hospital in Jamestown in connection with the two cases.

He is being held at the McLean County Jail in Washburn on $500,000 cash bail.