A deadly shooting at a Tuscaloosa apartment complex Sunday night is being investigated as a possible case of self-defense, authorities said.

Tuscaloosa police responded Sunday night to Aspen Village Apartments on a report of a shooting. When they arrived on the scene, they found Namarcus Giles Jr. dead.

The Tuscaloosa Violent Crimes Unit was called in to the lead the investigation.

TVCU Capt. Jack Kennedy on Monday said the investigation showed that a brother and sister lived at the apartment where the fatal shooting happened. They remained on the scene after the gunfire, as did other witnesses.

Giles had been in a previous relationship with the female who lived at the apartment. “It was reported that Giles had been physically abusive to her in the past,’’ Kennedy said.

Residents of the complex told investigators that on Saturday, Giles had made threats to come to the apartment.

He eventually did go the apartment on Sunday, where authorities say he broke down the door, entered and began to physically assault his ex.

The assault victim’s brother grabbed a gun and shot Giles, Kennedy said.

“The physical evidence on scene, as well as witness accounts, are consistent with this course of events,’’ Kennedy said. “As stated previously, law enforcement was immediately contacted and all persons present were cooperative.”

“At this time no arrest has been made,” Kennedy said, “as reported issues of self-defense are present.”

Once the investigation is complete, the findings will be presented to a grand jury to determine whether charges will be filed.