MONTPELIER, Vt. — A lawsuit filed by a Burlington police officer over head injuries allegedly suffered during training exercises two years ago at the Vermont Police Academy has made public details of an investigation that found other officers sustained similar injuries.

Trainees were participating in a scenario in which a trainer played the role of a hitchhiker encountered by the officer at the side of the road. In her lawsuit, Officer Erin Bartle, who is now working on the streets for the Burlington Police Department, said she was hit in the head multiple times on three separate occasions when participating in the exercise.

In one case Bartle said she was knocked to her knees and nearly lost consciousness while wearing protective equipment. She said she suffered multiple concussions.

After learning of Bartle's experience, Burlington Police Chief Brandon del Pozo asked a deputy to investigate. The investigation interviewed 10 Burlington officers who attended the last three training classes at the academy, located in Pittsford, and heard similar stories. It found that the officer injuries "while attending the VPA had been significant."

In the heavily redacted report that was released publicly, one Burlington officer said one of the trainers was a mixed martial arts expert who had two years of competitive fighting. They spoke of sharp blows to the head.

Police Academy Executive Director Richard Gauthier did not return a call Monday seeking comment.

Rebecca Kelley, the spokeswoman for Republican Gov. Phil Scott, said Scott "believes it's critical that our officers are trained using best practices that consider the well-being of the trainees and necessary skill development."

"It's our understanding the Criminal Justice Training Council is pursuing contracts with two entities for both an investigation of the complaint and review of the training itself. The Governor agrees this is appropriate, in light of the complaints," Kelley said.

Del Pozo also asked a use-of-force expert from the Baltimore, Maryland, Police Department to review the hitchhiker training exercise used at the academy. The review by Baltimore Police Sgt. Scott Swenson found the Vermont exercise caused head and knee injuries, hearing loss, vomiting and dizziness and other symptoms among the injured officers.

"Any drill that results in this many alleged injuries or possible diagnoses requires serious examination of training practices to ensure they are safe, feasible, objective based and are keeping with the standards of proper training," said Swenson's Sept. 12, 2018, memo to his superior.

The Vermont Police Academy, which is operated by the Vermont Criminal Justice Training Council, provides standardized training for Vermont police agencies that allows graduates to become certified as police officers. The hitchhiker exercise is designed to train officers how to respond to assaults.

In her lawsuit, Bartle, who began training in February 2017, said she was hit in the head by the trainer when she looked down while being handed identification. Unable to subdue the trainer with a baton and open hand strikes, she drew her firearm and was told she failed the exercise for trying to use her weapon.

In a second try, Bartle said she was hit in the head "with great force, knocking her to her knees, causing her to nearly lose consciousness." She was then failed for asking that the training scenario be suspended.

A week later during a third attempt she was also hit multiple times in the head. The blows caused concussions each time, her lawsuit said.

Bartle's attorney Jerome O'Neill said Monday that his client's experiences prompted Burlington police to look into the training practices.

In a memo to Burlington Mayor Miro Weinberger and in a separate letter to Gauthier, del Pozo asked for an investigation into the training practices at the academy.

"To me the bigger questions are what type of judgments led supervisors and staff to believe this scenario was acceptable in the first place, and then once the serious risks were actually demonstrated, why they elected to continue it without any sort of modification," del Pozo said in a June 12, 2018, email to Gauthier.

In a Sept. 12 letter to del Pozo, Gauthier said the Criminal Justice Training Council is seeking someone to assess the academy's training, but it would not conduct an internal review of del Pozo's complaints. Minutes of an Oct. 12 meeting of the council, however, show council members voted unanimously to review the academy's use-of-force training.