VERSAILLES, Mo. (AP) – A Missouri State Highway Patrol trooper has been charged with involuntary manslaughter in the drowning of a handcuffed Iowa man.

The Kansas City Star reports that a special prosecutor announced the charge Friday against Trooper Anthony Piercy outside the Morgan County Justice Center.

Piercy was transporting Brandon Ellingson for a breath test on May, 31, 2014, when the 20-year-old tumbled into the Lake of the Ozarks wearing an improperly secured life vest. The vest slipped off, and Ellingson, of suburban Des Moines, Iowa, drowned.

Piercy primarily patrolled roads and said previously he lacked training to handle the situation.

The drowning led to questions about a decision to merge the state’s water and highway patrol. A Legislative report found that the merger resulted in less training for troopers working on state waterways.