JEFFERSON CITY (AP) – The Missouri State Highway Patrol is investigating the weekend drowning of a 20-year-old Iowa man who was handcuffed and being transported on suspicion of boating while intoxicated at the Lake of the Ozarks.

Highway Patrol Sgt. Paul Reinsch said Monday that Brandon Ellingson was taken into a Water Patrol boat, handcuffed and placed in a life vest. Reinsch says officials are investigating whether Ellingson fell into the lake or jumped in and that it’s unclear why his life vest came off.

Reinsch says the trooper involved has been placed on administrative leave, which is standard procedure. He says the investigation likely would take at least a week.

Ellingson was from Clive, Iowa, and had been attending Arizona State University.