Jurors in the western U.S. state of Colorado have begun deliberations over the fate of James Holmes, who went into a suburban Denver movie theater three years ago, killed 12 people and left 70 wounded.
The panel of nine women and three men will determine whether Holmes was legally insane. He has pleaded not guilty by reason of insanity to 165 charges including murder.
Holmes, a 27-year-old former neuroscience graduate student from California, could face the death penalty if he is convicted of opening fire inside a midnight premiere of a Batman movie.
During the trial, two court-appointed psychiatrists testified for the prosecution that while the defendant is severely mentally ill, he was sane when he plotted and carried out the massacre.
The defense conceded that Holmes was the gunman who opened fire and killed the moviegoers, but it countered with two privately hired psychiatrists who concluded that Holmes is delusional and schizophrenic, and cannot be held legally accountable.
If Holmes is convicted of first-degree murder, a decision to spare his life in the penalty phase would result in a mandatory life sentence without the possibility of parole.