Ian Cramer, 42 of Bismarck, is due to appear in court on Friday on charges of felony manslaughter, fleeing a police officer and reckless endangerment after the death of Mercer County Sheriff’s deputy Paul Martin on Wednesday.
Mr Cramer had been driven to Sanford Health hospital by his mother Kris after suffering a mental health episode at around 4:30pm on Wednesday, police say.
When his mother got out of the vehicle, he took the wheel and smashed through an enclosed ambulance bay before speeding off, according to Bismarck police.
A Mercer County deputy spotted Ian Cramer in a Chevrolet Tahoe in Hazen, a community about 70 miles (113 kilometers) northwest of Bismarck, about an hour later.
The North Dakota Highway Patrol said in a statement that officers approached the SUV, but Ian Cramer sped off before they could apprehend him.
Shortly afterwards the vehicle veered out of lane and hit a sheriff’s vehicle parked along a state highway with its emergency lights activated.
Deputy Martin, 53, who was standing behind the vehicle preparing to lay down road spikes, was crushed by the vehicle and died.
Ian Cramer was taken to Sakakawea Medical Center in Hazen for evaluation before being transported to the McLean County Detention Center in Washburn.
Kevin Cramer issued a statement saying he was returning from Washington DC to North Dakota on Wednesday night, and said his family were grieving for the “family of the hero who tried to help Ian”.
“We ask the public for prayers for the lost officer’s family and colleagues who serve us every day and are grateful for all they do for us.”
The first-term senator said his son suffered from serious mental disorders which manifest in severe paranoia and hallucinations.
Before the crash, he had insisted on going to his brother Isaac, known as Ike, who died in 2018, Kevin Cramer said.
“Our daughter was able to track the car through Kris’ cell phone and lead officers to him in Mercer County, North Dakota. We don’t have more details right now but will work with authorities to properly inform the public,” Mr Cramer said.
Mr Martin was an 18-year veteran of the force who leaves behind a wife and three children, the patrol said.
Ike Cramer died aged 35 after suffering liver and kidney failure following a lengthy battle with alcoholism, according to the Bismarck Tribune.