A senior trooper is suing Oregon State Police, alleging his supervisor harassed and retaliated against him for taking medical leave and filing workers’ compensation claims for injuries suffered on the job.

Mark McDougal, 45, a 20-year trooper, suffered a severe spinal injury after he was run over by a suspect’s car in 2014 and then aggravated that injury in October while administering CPR to a suspect who had been shot and killed by a member of the Basin Interagency Narcotics Enforcement Team, the suit says.

McDougal separately injured his shoulder during defensive tactics training and required surgery. Earlier this month, he suffered a concussion on the job, after falling on snow and ice in the parking lot and striking his head on a patrol car’s bumper.

The suit alleges that McDougal’s supervisor, Sgt. Patrick Trippett, repeatedly mocked McDougal for his injuries, called him a gay slur around other troopers and made derogatory remarks about McDougal’s genitals in his criticisms of him for filing workers’ compensation claims.

“I do not take a step like this lightly. I am very dedicated to this job,’’ said McDougal, speaking on his own behalf. “My hope is to bring some change to make things better for the future younger troops.’’

McDougal’s suit comes amid similar complaints lodged last year against Trippett from six other troopers who have worked with McDougal in the Klamath Falls Area Command office.

The other troopers, in a 2018 letter to two state police captains, backed up McDougal’s allegations that they heard Trippett repeatedly call McDougal a derogatory name. The other troopers wrote that Trippett consistently failed to show competent leadership, using “offensive terms, name calling, disparaging comments, bully tactics and hypocrisy to define his leadership style.’’

“He belittles, insults and demeans to exert his superiority over the people he supervises and we are asking you to investigate and put a stop to it,’’ the six troopers wrote, in a signed letter to two police captains.

Oregon state police just learned of the lawsuit Monday and couldn’t comment on the pending litigation or a personnel matter, spokesman Capt. Tim Fox said.

Mark Banks, president of the Oregon State Police Officers Association, said he couldn’t comment because the plaintiff, McDougal, and the defendant, Trippett, in the lawsuit are both members of the union.

McDougal complained about the alleged harassment to state police supervisors but nothing was done, his attorney Michael Fuller said.

McDougal said he filed a complaint last fall with the state police Professional Standards Division, was interviewed but hasn’t been informed of any outcome.

McDougal also contends he was passed over for a promotion to sergeant in November, a post filled instead by a trooper on the job for three years who didn’t meet the minimum requirement for sergeant’s rank of working five years on the street.

McDougal said he didn’t have problems until he transferred from the North Plains office to Klamath Falls three and a half years ago. Before his Klamath Falls patrol post, he said he received support and appreciation from his supervisors for his work.

McDougal is seeking $2.5 million in economic and noneconomic damages from the state police and a court-ordered injunction to prohibit state police from the alleged discrimination.

The lawsuit was filed Sunday in Multnomah County Circuit Court.

-- Maxine Bernstein

Email at mbernstein@oregonian.com

Follow on Twitter @maxoregonian http://twitter.com/maxoregonian

Visit subscription.oregonlive.com/newsletters to get Oregonian/OregonLive journalism delivered to your email inbox