After killing the woman in the parking lot, the shooter entered the main sanctuary door, which was at the rear of the sanctuary, Aaron said at a later press conference.
"After doing so he began indiscriminately shooting," he said.
A church usher confronted the gunman, Aaron said, and was "pistol whipped" by the man.
"There was a significant struggle between the two," he said, adding, "During the struggle, the gunman shot himself, probably not intentionally, in the left pectoral muscle."
The usher, who was a licensed gun owner, went to his vehicle and retrieved his own fire arm, returned to the church and "made sure that the gunman didn’t make any more movements until the police department arrived," he said.
The shooter, whom police have identified as a "26-year-old African American individual," was being heavily guarded in a hospital, and is not believed to have life-threatening injuries, officials said.