A state appeals court on Friday rejected the latest appeal of a man sentenced to death in the murder of an Auburn University student abducted from campus and slain in 2008.

The Alabama Court of Criminal Appeals let stand the capital murder conviction of Courtney Lockhart in the killing of Lauren Burk, a freshman from Marietta, Georgia.

Prosecutors argued that Lockhart surprised Burk and forced her into her car at gunpoint, then made her undress in the vehicle and shot her in the back when she tried to jump out of her moving car. She died after being found along a roadside.

Lockhart claimed a gun went off accidentally, and he argued in an appeal that his defense was ineffective because it failed to hire a weapons expert. The court rejected the argument.

The appeals court also turned away Lockhart’s argument that a judge was wrong to reject his claim that the defense did an inadequate job of presenting his argument that previous military service left him with post traumatic stress syndrome or a traumatic brain injury that made him incapable that what he did was wrong.

The defense presented evidence that Lockhart served in combat zones in Iraq and was affected afterward by the experience. A judge cited Lockhart’s military experience and training in rejecting claims that he could have shot Burk accidentally.