A 24-year-old Rolla man has been charged with first-degree assault in the death of his stepfather.

Marcelus E. St. Clair, 24, of Rolla has been charged with first-degree assault after his stepfather, Steven Sheffield, 50, died after an altercation.

At 9:43 p.m. Thursday, the Rolla Police Department received a 911 call from a resident in the 1200 block of Maple Street requesting an ambulance and police officers for an unresponsive male who had been involved in a domestic disturbance with his stepson.

Officers responded to the residence and located the victim, Sheffield, of Rolla, lying on the living room floor unconscious, apparently as a result of a physical altercation between him and his stepson.

Sheffield was transported by Phelps County Ambulance to the Phelps County Regional Medical Center. He was later air-lifted to Cox South Medical Center in Springfield for severe internal bleeding, and he later died as a result of his injuries.

St. Clair, the suspect’s stepson, of Rolla, was arrested and is currently incarcerated in the Phelps County Jail in lieu of a $250,000 bond for first-degree assault.

Rolla Police Chief Mark Kearse called Sheffield’s death “a terrible tragedy.”

“It was a family argument that got out of hand,” Kearse said. “It’s a terrible tragedy.”

In discussions with the prosecutor, Kearse said Phelps County Prosecutor Courtney George opted for the first-degree assault charge, although Kearse did not rule out other charges.

St. Clair pleaded guilty last year to an assault charge, according to Missouri Casenet.

On Saturday, an autopsy was performed in St. Louis, and a final determination as to the cause of death is still pending due to further analysis.

Persons who might have additional information pertaining to this case please are asked to call the Rolla Police Department at (573) 364-1213 or the Rolla Police Department’s confidential tip hotline at (573) 364-0111.