OKLAHOMA CITY -- The military background of a pharmacist accused of shooting and killing a teenager who tried to rob him is being questioned.

The 57-year-old veteran made national news after he shot and killed a 16-year-old would-be robber inside an Oklahoma City pharmacy. The district attorney charged pharmacist Jerome Ersland with murder, saying he went too far by shooting the teen several more times after he was already down.

"There are limitations to a person's ability to defend themselves, and that limitation comes when the imminent threat is over," said Oklahoma County District Attorney David Prater.

After the shooting, Ersland told police and reporters that he was a veteran of the first Gulf War and suffered from post-traumatic stress disorder.

But Ersland's military records released to the Oklahoma County District Attorney's office dispute that. The records show Ersland being at Altus Air Force Base.

"What he did in the past...if he says he was the last king of Scotland, what difference does that make?" said Ersland's attorney Irven Box.

The district attorney disagrees. Prater said everyone's background is being looked at in this case, and that includes Jerome Ersland.

"Justice is done so many times involves looking into the perpetrators background and determining why an event may have occurred and seeing if that mitigates the situation at all," Prater said.

But Ersland's attorney said the only thing that should matter now is what happened inside the pharmacy.

"Forty-six seconds, it's on video. It happened. Armed masked men came in....your money or your life, Mr. Ersland reacted. What he might have done five-years-ago, 10-years-ago or 20-years-ago, I don't believe has any particular relevance to this particular crime that he was a victim of," Box said.

Ersland is out of jail on $100,000 bond, and has since returned to work at that same pharmacy. He's not allowed to have access to guns, knives or other weapons.