The Missouri State Highway Patrol is investigating how a handcuffed 20-year-old man stood up on a moving Patrol boat and either jumped or fell overboard Saturday evening.
Highway Patrol divers recovered Brandon Ellingson's body around 11:30 a.m. Sunday.
Ellingson was arrested Saturday evening for boating while intoxicated and was in Highway Patrol custody.
"The subject was placed under arrest, put in handcuffs, and a life vest was put on him, and [he was] placed in the boat to be taken by the trooper," Sergeant Paul Reinsch of the Highway Patrol said.
"Once the subject entered the water, at some point in time that life vest came off. And the investigation is trying to determine how that happened."
It happened around mile marker 3.5 of the Gravois Arm of the Lake of the Ozarks, right outside Bumps Barefoot Bar.
Staff there saw the Highway Patrol search boats but did not immediately know what had happened.
"Neighbors came in, customers, letting us know that they were dragging for a dead body," Linda Enyard, manager of Bumps Barefoot Bar, said.
"You hear about it in other areas of the Lake, but never this close. And it kind of was a little...a little disturbing. I think it just kind of put people in a sad mood."
As is protocol in critical situations, the involved trooper has been placed on administrative leave and Highway Patrol is conducting a step-by-step review of the incident.
"Once the trooper realized that the subject had entered the water, he did try to throw a line to the subject," Sgt. Reinsch said.
"When that was unsuccessful, he did enter the water himself and try to rescue him...made several attempts to locate the subject, but wasn't able to do that."
Brandon Ellingson was from Clive, Iowa, and had been attending Arizona State University.
The final report on the incident could be finished by the end of the week or early next week.