Sef-defense With AR-15

From the Nov. 26, 2015 Wyoming Tribune-Eagle:

 - While detectives continue to investigate a dual homicide that happened here Sunday night, the Cheyenne Police Department announced Friday that at least one of the deaths seems to have involved self-defense.
Justin Morrison and Darius Mathis, both 23 and of Cheyenne, were killed by shots fired around 11:30 p.m. Sunday outside 4523 E. 14th St. in east Cheyenne.
"The investigation's not completed, and we're still waiting on some of the physical evidence," police spokesman Officer Dan Long said. "(But) they've gotten a lot of that preliminary information back."
Newly released information says Mathis, who died on scene, was shot with an AR-15 rifle by a third person, identified by police as 20-year-old Brandon Painter.
Painter reportedly was a resident of the house along with Morrison and two others.