A weekend shooting that killed a 29-year-old man is believed to be an act of self-defense, the Athens police chief said.

Christopher Demond Carter, of Harvest, was killed by his ex-girlfriend's new boyfriend on McClung Lane after shooting and injuring the couple, according to Chief Floyd Johnson.

After Carter showed up at the boyfriend's home just east of Elkmont Road, an argument erupted and shots were fired. Police were called the scene just before 4 a.m. Sunday. Johnson said Carter shot his ex-girlfriend and her boyfriend -- hitting the woman's leg and the man's arm. Then, the boyfriend went into the house, grabbed a pistol and shot Carter, Johnson said. Carter died in the street.

"I think this is a case of self-defense," Johnson told AL.com.

The boyfriend and girlfriend were treated and released from Athens-Limestone Hospital.

"I (met) with our investigators this morning; we went over evidence collected and statements taken in the case," Johnson said in a news release. "Our investigation will be continuing for several weeks to come. We have evidence that will have to be sent for examination and analyses."

Johnson said once the investigation is complete, the case will be handed to Limestone County District Attorney Brian Jones for presentation to a grand jury. A grand jury will be asked to determine whether the boyfriend should be charged in Carter's death.