Agents for the Iowa Department of Criminal Investigation were again on the scene Tuesday in Cincinnati where Davis Tyler Opperman, 23, died Sunday.

An autopsy performed Monday by the Iowa State Medical Examiner’s Office determined Opperman’s death was caused by a single gun shot wound to the head. The official manner of death has not yet been determined.

Opperman’s wife, Casey Opperman, called 911 at approximately 3:30 a.m. Sunday to report that her husband had killed himself at 112 N. Liberty St. Upon arrival, law enforcement officials and emergency medical personnel found Opperman dead at the scene.

Since then, the house has been guarded around the clock by Appanoose County Sheriff’s deputies.

The Oppermans were married in August.

A previous husband of Casey Opperman’s, Brad Tuttle, died of a gunshot wound July 2006 in Green City. Mo., and was declared a suicide by the Sullivan County coroner.

Sullivan County Sheriff Bill Hayes, who investigated the incident, said he was satisfied that Tuttle’s death had been a suicide.

Members of Tuttle’s family have said they do not believe he took his own life.