text: The Aurora movie theater shooter studied brain disorders as a doctoral student before he killed 12 people and injured 70 more in one of America's deadliest mass shootings. Prosecutors said James Holmes, 27, was once a sought-after neuroscientist-in-training, but evidence shows that months before the shooting he was preparing for violence. The prosecution is trying to prove that Holmes was not mentally ill and knew exactly what he was doing the night of July 20, 2012, when he opened fire during the midnight premiere of the Batman film 'The Dark Knight Rises'. If the 12 final jurors, chosen from a pool of 9,000, decide that Holmes was mentally ill at the time of the shooting, he will be committed indefinitely to a state psychiatric hospital. If not, prosecutors will press for the death penalty over life in prison without parole. Aurora movie theater shooter James Holmes studied brain disorders as a doctoral student before he killed 12 people and injured 70 more in one of America's deadliest mass shootings . Prosecutors said, in the months before the shooting, Holmes told a classmate he wanted to kill people, had fallen out of favor with his professors, and had stopped seeing his psychiatrist. He then sent her threatening text messages and mailed her his journal in a package with $20 bills, prompting her to alert University of Colorado campus police. Holmes also stockpiled weapons, ammunition, tear gas grenades and riot gear, and rigged his apartment to become a potentially lethal booby trap, cranking techno music in an apparent attempt to lure someone into opening his door. One neighbor who came to complain narrowly avoided a fiery explosion by walking away. Iris Eytan, Holmes former attorney, believed he was 'absolutely out of his mind'. 'Look at his eyes, they're completely dilated,' she said, referencing a mug shot showing Holmes with his hair dyed comic-book orange. 'He was under the influence of something, and I believe it was mental illness,' she said. Psychosis is something Holmes knew all about. Before the shooting, he was preparing to give a class presentation on 'MicroRNA Biomarkers', which provide a biological basis for psychiatric and neurological disorders. About the same time, he was amassing deadly firepower: Two Glock pistols. A shotgun. An AR-15 rifle. Boxes upon boxes of ammunition — 6,295 rounds in all. Police who searched his apartment also found prescription medications for anxiety and depression, 50 cans and bottles of beer, paper shooting targets, and a 'Batman' mask. Prosecutors believe it is all evidence of meticulous plotting, proving that the mass murder was deliberate and calculated. Prosecutors said James Holmes, 27, was once a sought-after neuroscientist-in-training, but evidence shows that months before the shooting he was preparing for violence . The prosecution is trying to prove that Holmes was not mentally ill and knew exactly what he was doing the when he opened fire during the midnight premiere of the Batman film 'The Dark Knight Rises' They pointed out that Holmes searched online for 'rational insanity,' and took haunting selfies the night of the shooting that show him sticking out his tongue and smiling with a Glock under his face. 'He didn't care who he killed or how many he killed, because he wanted to kill all of them,' Prosecutor Karen Pearson said. Holmes' former psychiatrist and two court-appointed doctors who spent days interviewing him will be questioned during the trial. They will likely be asked to explain how a seemingly harmless college student without so much as a traffic ticket on his record could march up and down a theater, mercilessly shooting down those who tried to flee. Holmes was a shy teen who graduated with highest honors from the University of California, Riverside, and then applied for elite doctoral programs. He landed at the University of Colorado's Anschutz Medical Campus near Denver, one of just six students awarded entry into the exclusive doctoral program in June 2011. He also earned a National Institutes of Health grant for top performers. But by his second semester, he was flunking key exams and wasn't asked to join his professors' labs. A month before the shooting, Holmes officially withdrew from the university and saw his psychiatrist one last time before, according to his classmates, he fell out of sight. From July 5 to July 18, two days before the attack, Holmes logged onto a dating website with the handle 'classicjimbo.' His profile said he was seeking 'casual sex' and asked 'Will you visit me in prison?' If the 12 jurors decide Holmes was insane at the time of the shooting, he will avoid prison and be committed indefinitely to a state psychiatric hospital . In this Jan. 20, 2015 courtroom file sketch, James Holmes, left, and defense attorney Tamara Brady are depicted, as they sit in court on the first day of jury selection in Holmes' trial .
target: James Holmes was once a doctoral student and neuroscientist-in-training .
  But prosecutors say in the months before the shooting he was preparing for violence, amassing weapons and sending threatening text messages .
  Said Holmes searched online for 'rational insanity' knew exactly what he was doing when he opened fire at the 2012 Batman premiere .
  If the jury finds Holmes was mentally ill at the time of the shooting, he will avoid jail and be committed indefinitely to a state psychiatric hospital .