The Georgia Supreme Court on Monday upheld the murder conviction against Alberto Martinez, a former soldier who killed a fellow infantryman shortly after returning from heavy combat in Iraq.

The court rejected claims that Martinez deserved a new trial because his lawyers failed to tell jurors he suffered from Post Traumatic Stress Disorder when he killed Spc. Richard Davis, 24.

Justice Harris Hines, writing for a unanimous court, said PTSD might explain why Martinez would snap and do something in reaction to some stimulation. But the disorder "could not explain Martinez's subsequent actions of repeatedly stabbing Davis and engaging in a conspiracy to cover up the murder," Hines said.

The grisly Muscogee County murder loosely inspired the movie, "In the Valley of Elah." Davis died on July 12, 2003, shortly after the soldiers returned to Fort Benning from a six-month tour in Iraq and Kuwait.

According to testimony, Martinez, Davis and three other soldiers went out for a night of heavy drinking to celebrate their return. After Davis insulted a dancer at a Columbus strip club, the soldiers got in Martinez's car and drove off. Martinez soon pulled over and ordered Davis out. After two soldiers in the car began fighting with Davis, Martinez stepped forward and began stabbing him, at least 33 times in all.

Martinez and two of the soldiers later returned to the scene, moved Davis' body and set it on fire.

Martinez's appellate lawyer, David West, had told the court that, before trial, a psychologist interviewed Martinez and concluded he might have entered into a dissociative state, triggered by the fighting, on the night of the murder. Martinez may have believed he needed to defend himself because he perceived Davis to be a threat, the psychologist said. But Martinez's trial attorneys did not present this evidence —- or military medical records indicating Martinez may have PTSD —- to the jury.

In Monday's ruling, Hines wrote that Martinez's trial lawyers provided "ample justification" for not pursuing this insanity defense.

They contended one of the other soldiers, Jacob Burgoyne, killed Davis. At trial, they tried to discredit Burgoyne, who pleaded guilty to voluntary manslaughter and testified for the prosecution. Although this defense failed, this strategy was not unreasonable, Hines said.