A Florida boy is facing first-degree murder charges for allegedly shooting his mother’s boyfriend during a domestic dispute early Wednesday morning.

The 15-year-old from Mulberry, Florida, allegedly got a 12-gauge shotgun from his room and shot Paul Gregg Jr., 37, in the back.  The victim was reportedly pronounced dead at the scene.

According to arrest affidavit obtained by the Orlando Sentinel, the 15-year-old told police he brandished a shotgun and killed his mother’s boyfriend because he had “had enough,” and feared what Gregg would do if he was not stopped.

According to the Orlando Sentinel, the suspect’s mother, Jessica Whidden, had not been home for several nights because of altercations with Gregg.  When she came to the home on Tuesday night before going to dinner with friends, the couple reportedly got into an argument, and argued again upon her return the next morning, when the dispute escalated.

According to the arrest affidavit, Gregg grabbed a knife and followed Jessica to the bathroom. From there, Gregg allegedly said he “wished he could kill her and that he would torment her until she committed suicide,” while waving around the weapon.

The teen reportedly pointed a gun at Gregg in the living room of the home. When Gregg then headed to a dresser near a master bedroom closet where more guns were kept, the boy shot him in the back, according to the Daily News.

The mother and son left the home following the shooting and contacted police from a nearby church.

According to WFLA, Polk County Sheriff Grady Judd said late Wednesday that detectives are determining whether the teen shot in self-defense or if he murdered his mother’s boyfriend.

Polk County Sheriff’s Office told WTSP that Gregg and Whidden had been in a relationship for five years, and were heavy drinkers. Gregg reportedly had arrests for driving under the influence and battery.

The 15-year-old has no prior arrests. It is not known whether police will charge him as an adult.

Photo: Polk County Sheriff