A man who once worked as a police officer in Massachusetts has been charged with assaulting a man in custody by punching him multiple times without legal justification, according to federal prosecutors.

Former Weymouth police officer Justin Chappell, 43, was charged with one count of deprivation of rights under color of law resulting in bodily injury, the U.S. Attorney's Office announced Thursday.

The charging document states that on July 2, 2022, Chappell was working as a police officer for the Weymouth Police Department when he punched a handcuffed man approximately 13 times with a closed fist while he was arresting him.

Weymouth police Chief Richard Fuller said that on the night of July 2, 2022, officers were dispatched to a report of an intoxicated man causing a disturbance at about 7:30 p.m.

"Officers had responded to the address earlier for the same male leaving the residence operating a vehicle while under the influence," Fuller wrote in a statement.

When officers returned to the home, a woman directed Chappell to the man. Fuller said Chappell confronted the man, "who was heavily under the influence of alcohol, confrontational and non-compliant."

Chappell's body camera captured his exchange with the suspect and the violent struggle that ensued. Chappell struck the man with a baton several times before another officer arrived to help apply handcuffs.

Fuller said the second violent struggle occurred when officers tried to place the suspect inside a cruiser.

"The suspect violently resisted being placed in the cruiser and threw his elbow at the officers while breaking free from their grasp. He also spit on the officers. As the struggle continued, Chappel delivered several closed-fist strikes to the suspect's head," Fuller said.

In his arrest report, Chappell wrote, "After being physically assaulted by [him] and spit on, I applied four to five distraction techniques with a closed fist on the top of [his] head. My intent was to apply enough intensity of those techniques in order to gain compliance."

Views of this altercation were also recorded by multiple body cameras and a camera inside the cruiser.

"The investigation found that several of these strikes were unnecessary and improper," Fuller said. "Chappell was found to have used excessive force."

According to Fuller, the Weymouth Police Department's policy requires a supervisor to review the footage because of the use of force. That supervisor identified the issues, which led to an internal affairs investigation.

Chappell resigned from the Weymouth Police Department on July 11, 2022, just over a week after the incident. His resignation came before he was set to have a termination hearing, which was scheduled after the initial investigation.

"My experiences, careers, and deployments prior to being a police officer have proven difficult to balance in law enforcement at this time," Chappell wrote in his resignation.