OPELIKA, Ala. – A former Army soldier who claimed to be mentally disturbed from his deployment in Iraq was convicted of capital murder Thursday in the abduction and shooting death of an Auburn University student from Georgia.

Jurors deliberated about six-and-a-half hours over two days before convicting Courtney Lockhart, 26, of rural Smith Station, in the killing of 18-year-old freshman Lauren Burk of Marietta, Ga.

Wearing a black suit, Lockhart sat calmly with his lawyers and showed no emotion when the verdict was announced. He had pleaded not guilty and not guilty by reason of mental defect, and did not testify.

The jury has the option of recommending a sentence of death or life without parole in the penalty phase, which was to begin Thursday afternoon. The judge is not bound by the jury's recommendation.

Burk was abducted on the night of March 4, 2008, as she got into her car in a campus parking lot after visiting her boyfriend. According to statements given by Lockhart, he pulled a gun on the screaming student, trying to rob her, and forced her into her car as he drove it off.

Lockhart said he ordered her to disrobe, not to have sex with her but because he thought it would make her less likely to escape the car. At one point Lockhart said he spoke of his problems: "We started talking about how my life was over. She said she could help me get a job," he said in a written statement.

But Burk was shot in the back at close range as she opened the door and jumped from the car.

I just had the gun right there and it went off," Lockhart was heard saying on a mostly garbled videotape played at the trial.

The nude student collapsed on the road and bled to death as Lockhart drove off and later burned the car on the Auburn campus. He was captured three days later in Phenix City after a car chase when he was a suspect in a robbery attempt in Newnan, Ga.

Prosecutor Kisha Abercrombie said in closing arguments Wednesday that the defendant knew his revolver was ready to fire as he drove Burk's car on rural roads near Auburn.

He knew that the gun was cocked. After he killed her ... he started covering his tracks," Abercrombie said.

But defense attorney Joel Collins argued that if Lockhart had wanted to kill the student, he could have done it when he first grabbed her in the parking lot or pulled off the road at any time and shot her.

Lee County District Attorney Nick Abbett raised Lockhart's military experience as a reason the shooting wasn't accidental.

Someone who has been in combat knows how to handle a weapon," Abbett said. "He pointed the gun at her, with the hammer cocked back.

Though Lockhart's attorneys argued he had mental troubles, a psychologist who testified for the defense could not say for certain that he suffered from post-traumatic stress disorder.

Another psychologist for the prosecution told the jury that Lockhart showed no signs of mental disorder and understood that what he did was wrong.

Lockhart's former fiancee, who is the mother of his 4-year-old daughter, testified that the former Army soldier from rural Smith Station was "a very nice, sweet, funny and caring" man before he went to Iraq.

But Nicole Threatt said the man who returned was very different.

He had an 'I don't care attitude,'" Threatt said. She said he bathed less frequently and said she sometimes found him standing by himself in a closet. He didn't like people to walk behind him.

She said Lockhart became "emotionally numb" after two events in Iraq: One when he and other soldiers came under friendly fire and another was when a close friend was killed.

Things didn't matter to him as much as before," she testified.