AUBURN — A 72-year-old Army veteran is suing the Auburn Police Department for civil rights violations and use of excessive force, which he claims led to serious injuries that required heart surgery.

The complaint, filed July 23 in U.S. District Court, claims Auburn police wrongfully arrested and injured Ronald Deschaine outside his home at 72 James St. when he approached officers who were investigating his neighbor.

Deschaine, a former Army helicopter pilot who served during the Vietnam War, claimed that as the investigation unfolded, he was speaking to a police officer who was seated in a cruiser, the third to arrive.

According to the lawsuit, the officer told Deschaine to step away from the vehicle, at which point Officer John Chamberlain called out, “You are going to jail.”

Deschaine, who claimed he was afraid of Chamberlain, continued facing the unnamed officer’s cruiser and said, “You stay away from me,” at which point Chamberlain ran and tackled Deschaine from behind, “knocking him violently into the police cruiser,” according to the complaint.

The lawsuit claims the action “required immediate medical attention, including heart surgery.”

The lawsuit names Chamberlain, unknown officers, an unknown supervisor, former Auburn Police Chief Phil Crowell and the city of Auburn as defendants.

The claim alleges that after Deschaine was tackled, he was in severe pain and confused as Chamberlain attempted to place handcuffs on him, and Deschaine did not initially cooperate.

Deschaine claimed that another unnamed officer hit him with a baton and threatened to use a Taser on him, and that Deschaine suffered “significant lacerations and bruising” from the handcuffing.

According to the lawsuit, Deschaine was charged with refusal to submit to arrest, but no criminal charges were ultimately pursued by the Androscoggin County District Attorney’s Office.

In an emailed statement Tuesday, Auburn City Manager Peter Crichton said the Maine Municipal Association’s Legal Services Department is working on the lawsuit.

“At the same time, the (police) department is conducting an internal investigation on what took place to determine what action, if any, should be taken,” he said.

Crichton declined to comment further.

A spokesman for the Maine Municipal Association said an outside law firm, Drummond Woodsum, will be working on a response to the lawsuit.

According to the lawsuit, Deschaine worked a number of jobs after his military service and retired in 2007 “following a heart attack that left him in a weakened condition.”

The lawsuit claims he was not armed and not threatening anyone during the 2016 incident.

It also claims another police officer and an unnamed supervisor “took no steps to stop Chamberlain and (the first unnamed officer) from using excessive force against Deschaine.”

The lawsuit says Chamberlain was instructed by a police dispatcher to bring  Deschaine to the hospital for care, and upon reaching the hospital, “Chamberlain initially refused to remove the handcuffs so that a doctor could examine him.”

It states, “Only reluctantly did Chamberlain finally remove one of the handcuffs.”

The lawsuit alleges that Crowell, the chief of police, failed to properly supervise and discipline Chamberlain for his actions, and claims Chamberlain had been involved in “numerous situations that have led to complaints being lodged about his excessive use of force.”

Deschaine is represented by lawyers Michael J. Waxman and William Maselli of Portland. Waxman did not respond Tuesday to a request for comment.