COLUMBUS, Ohio (AP) — A firearms instructor failed to make sure his gun was empty and fired a fatal shot into the chest of prisons department officer during a training exercise in April, according to investigative records released by the victim’s family.

The trainer was standing in front of Lt. Randy Osborne to give him additional instructions when he pulled the trigger, hitting Osborne just above his protective vest, according to the Ohio Highway State Patrol report.

David Pearson, an instructor with the state corrections department, pleaded not guilty in early August after being indicted on a misdemeanor charge of negligent homicide. Pearson’s attorney declined to comment on the report, saying a pre-trial hearing is scheduled in September.

Pearson was the lead instructor during the training exercise on April 9 at a state corrections department facility in Pickaway County. He told investigators that he was demonstrating drawing his weapon during what was supposed to be a drill with no live rounds.

“I thought I was clear. I thought I was good. I thought it was clean,” Pearson told investigators.

Osborne, 43, worked on special operations teams with the corrections department and served at the state prison in Lucasville.