An investigation is underway after an off-duty DeLand police officer shot and killed his uncle during a family squabble at a home in Deltona, according to the Volusia County Sheriff's Office.

Authorities say 51-year-old Bobby Harrelson, a DeLand police officer who was off-duty at the time, said he shot 68-year-old Raymond Davis, his uncle, because he was choking the officer’s mother, 76-year-old Hazel Hinds, during an argument.

The Volusia County Sheriff's Office is investigating the deadly shooting.

Deputies were dispatched to the home on Tradewinds Drive in Deltona after deputies received a 911 call about the shooting at 6:34 p.m.

When deputies arrived to the scene a few minutes later, Davis was already dead. Harrelson initially told deputies he retrieved the gun and fired because his uncle was choking his mother during a "heated argument and he was unable to break it up."

The argument took place in the living room.

No one else was home at the time of the shooting. The shooter and his mother were being interviewed at the scene and no charges have been filed, deputies said.

The State Attorney's Office has been called in to investigate the shooting. The Florida Department of Law Enforcement won't be involved in the investigation because the police officer was off-duty at the time of the shooting.

This isn't the first time officer Bobby Harrelson has been involved in a shooting. 

In January 2012, Harrelson fired several rounds at two men, injuring them after they allegedly aimed a pellet rifle at him. The incident also left a neighbor's dog and a 2-month-old baby girl injured by stray bullets.