The parents of a teenage robbery suspect killed by Cottonwood Heights police are suing the officer who fired and the department, alleging their son didn’t pose a threat and officials covered up the officer’s negligence.

They argue that by shooting their son, 19-year-old Zane James, in the back and firing stray rounds into a residential neighborhood, Cottonwood Heights officer Casey Davies had the potential to do more harm to bystanders than James, according to court documents filed Thursday in U.S. District Court.

Cottonwood Heights Police Chief Robby Russo declined to comment on the allegations Thursday. He had previously described James to The Salt Lake Tribune as "a known criminal, a violent criminal,” and said he thought the shooting was justified.

Tiffany and Aaron James say their son was a talented hockey player with ambitions to play through college and perhaps professionally. But after he suffered repeated concussions, his doctor recommended he stop playing.

“He was forced as a young man to basically reevaluate what the rest of his life was going to look like,” his father Aaron James said.

After James lost the sport he loved, he developed an opioid addiction from the pain medication he was prescribed, his parents said. That later turned into a heroin addiction, which he tried to overcome multiple times, they added.

James was killed May 29, 2018, after police say he robbed a store in Sandy with an airsoft gun. Davies, who was off-duty, heard a radio dispatch about the robbery around 6:10 a.m., and Davies and another officer decided to pursue James. James also matched the description of the suspect in another armed robbery from earlier that day.

James crashed his motorcycle turning onto a residential street and slid with it until it stopped. He got up to run, but the lawsuit notes he was “limping seriously.” The lawsuit alleges that without yelling commands at James to stop, approximately two minutes after he heard the initial radio call, Davies fired four times.

Initial reports given to media, in addition to statements from officers given to Salt Lake County prosecutors, say Davies ordered James to stop and show his hands.

Two of the bullets struck James, while the other two shots missed. One bullet went through James’ shoulder into his spinal cord, and he was paralyzed from the neck down. He died three days later in a hospital, after he chose to stop treatment, according to the lawsuit.

His family isn’t sure whether the bullet caused James’ paralysis, or if it was a result of officers moving James’ head and neck after he was shot. Body camera footage of the aftermath of the shooting shows police didn’t stabilize James’ head.

The lawsuit claims Davies didn’t act reasonably that Tuesday morning, saying he should have known James was severely injured in the motorcycle crash and couldn’t flee far, and that he never had any dangerous weapons in his hands. The lawsuit argues he wasn’t a threat to officers or citizens and shouldn’t have been shot.

The lawsuit also alleges that Davies lied about what he saw, and that the department later tried to misconstrue the facts of the case to protect Davies. It claims Davies lied by saying James was reaching into his pockets when the officer fired and that he broke his running stride when fleeing “like he was reaching for a gun," according to the lawsuit.

“But that claim makes no sense because Zane knew he did not have a real gun, so why would he reach for a toy gun, knowing armed officers were close behind?” it asks.

Attorneys for James’ parents also quote witnesses who dispute the other pursuing officer’s statements to investigators. Private investigator Shawn Merlin interviewed one of the witnesses soon after police left the scene, and attorneys talked to another witness more recently.

Witnesses say the other officer, identified in the lawsuit only by the last name Betenson, arrived at the crash site after Davies fired his fourth shot at James. That contradicts Betenson’s statements to prosecutors that he saw the crash and that he saw James appear to be reaching for something as he ran.

“The above statement by Officer Betenson is false or exaggerated,” the lawsuit states.

Merlin said at Thursday news conference that the witness he spoke with said police didn’t show restraint and lacked urgency in rendering aid to James after he was down. Merlin said police didn’t interview those witnesses.

Tiffany and Aaron James said at the same news conference that they wanted Merlin to investigate because Cottonwood Heights police had targeted their son after officers learned of his opioid addiction.

Merlin had helped get robbery charges filed against James dismissed after finding evidence that James couldn’t have been the suspect, the parents said.

The lawsuit also questions how Betenson perceived James as “some imminent risk” if Betenson did not draw his gun at James.

Neither Davies nor Betenson recorded the confrontation with dash or lapel cameras, which the lawsuit claims is not responsible. The only footage of James’ interactions with police comes after he is shot, when a third officer arrives.

Many of these issues — such as witness accounts that conflict with officer statements, why Davies joined a pursuit when he was off-duty, and why James was shot in the back — should have been addressed in the Salt Lake County District Attorney’s investigation of the shooting, but weren’t, the lawsuit claims.

Salt Lake County District Attorney Sim Gill said Thursday he sympathizes with the family, but that many those questions are beyond the scope of his review, which is meant to determine whether an officer was legally justified in using lethal force.

“Things that may be relevant to them for the purposes of a civil lawsuit are not necessarily the same things that are of relevance or consideration for us when we’re doing out shooting review,” he said.

He also said his office never received a list of new witnesses from the family.

Tiffany and Aaron James said they filed the lawsuit only after going to Cottonwood Heights police, the city’s mayor and prosecutors to discuss what happened and getting nowhere.

In addition to money for damages, James’ parents are asking for all Cottonwood Heights officers to use vehicle dash cameras and carry non-lethal as well as lethal weapons while on patrol, and to prioritize non-lethal weapons. They also ask the department to provide and require annual training on non-lethal and lethal force and to implement regular training on the management of situations like James’, to be in compliance with federal and state constitutional requirements.