Authorities say a man accused in a birthday party shooting at a Lanier Islands lake house told them he fired shots in self-defense.

On Monday in Magistrate Court, he faced charges of aggravated assault, aggravated battery and possession of a gun by a felon. Andrew Demetri Joyce, 23, of Decatur is accused of shooting Malik Davis, 23, of Union City at the Aug. 16 party.

Hall County Sheriff’s Office Investigator Tom Wilson testified Monday about a video obtained from an anonymous sender four to five days after the incident.

Two men are seen arguing about a girl when Davis enters the argument, Wilson said. Witnesses told authorities that Davis wanted to break up the fight.

After Davis moves closer, another man is seen raising his right arm, and two shots are heard.

“You can clearly see (Davis) clench his chest, at which time the crowd is running every direction, most trying to get out of the lake house,” Wilson said.

The woman celebrating her birthday, Wilson said, is seen in the video following the alleged shooter around “calling his name, Drew.”

On cross-examination, Joyce’s counsel Rose Priddy asked about any corroborating proof that would show Davis was indeed breaking up the fight and not seeking to participate.

When Wilson visited Davis at the hospital, the alleged victim couldn’t speak due to tubes in his mouth.

“The bullet went in under a rib, went through his lung, tumbled through his intestines through his spleen and out his lower left side, his back,” Wilson said. One of two needed surgeries involved removing Davis’ spleen.

The case moved on to Superior Court.