James Holmes, Colorado theatre shooter, trial starts jury selection

Jury selection has started in the Colorado theatre shooting trial after a judge called an unprecedented pool of 9,000 potential jurors to hear the death penalty case.

The first wave of potential jurors reported to a courtroom Tuesday to hear the judge explain the process and fill out a form gauging whether they are suitable to be brought back for further questioning.

It will take weeks to come up with a panel that will decide if defendant James Holmes was sane at the time of the shooting and recommend whether he should be executed if convicted.

• Mass shootings on the rise, FBI says
• Guns used in Colorado theatre shooting legal in Canada

Holmes has pleaded not guilty by reason of insanity to killing 12 people and injuring 70 others in the July 20, 2012, attack on the Denver-area movie theatre.

Some potential jurors carried books or newspapers or looked at their cellphones as they waited to get through security in the hallway, their second screening since entering the courthouse.

9,000 potential jurors

Holmes sat quietly and rocked slightly back and forth in his chair on Tuesday just hours before the start of the arduous process of choosing a jury to decide whether he was sane when he opened fire in a packed Colorado movie theatre.

Holmes was dressed in civilian clothes and with no visible restraints, though the judge had ordered him to be tethered to the floor in a way the public couldn't see for the trial. His dark hair was neatly trimmed, and he had a medium-length curly beard and wore oval-shaped reddish glasses.

The 9,000 person jury pool will be winnowed to a handful in the weeks ahead to hear the death penalty trial that could last until October.

The scope of jury selection and the trial is a testament to the logistical hurdles of trying the rare case of a mass shooter who survives his own attack.

"The public is going to get an insight into the mind of a killer who says he doesn't know right from wrong," said Alan Tuerkheimer, a Chicago-based jury consultant. "It is really rare. It just doesn't usually come to this."

In the 2½ years since the shooting, the case has sparked an emotionally charged debate, with Holmes's parents begging for a plea deal that would save his life while many survivors and family members of victims have demanded that he be put to death.

12 died in attack

Twelve people died and 70 were injured in the attack during a midnight showing of a new Batman movie. Holmes, 27, was arrested as he stripped off his combat gear in the parking lot of the Century 16 movie theatre.

He later pleaded not guilty by reason of insanity to multiple counts of first-degree murder and attempted murder.

The public is going to get an insight into the mind of a killer who says he doesn't know right from wrong.- Alan Tuerkheimer, a jury consultant

If jurors find him guilty, they must then decide whether to recommend the death penalty. If Holmes is found not guilty, he would be committed indefinitely to the state mental hospital.

Defence attorneys acknowledge Holmes was the gunman in the July 20, 2012, attack but say he was in the grip of a psychotic episode at the time.

Under Colorado law, defendants are not legally liable for their acts if their minds are so "diseased" that they cannot distinguish right from wrong. Part of the reason the case has dragged on so long is the battle over whether that standard applies to Holmes.

Few details on those arguments have been made public. Prosecutors and defence attorneys remain under a long-running gag order, and court documents detailing the issue have stayed under seal.

Holmes's sanity was evaluated by a state psychiatrist but the results were not made public. Prosecutors objected to the findings and persuaded a judge to order a second evaluation. Those results were contested by the defence.

Prosecutors previously rejected at least one proposed plea deal made by attorneys for Holmes, criticizing the lawyers for publicizing the offer and calling it a ploy meant to draw the public and the judge into what should be private plea negotiations.

Survivors ready for trial

Survivors of the attack and family members of victims have had a long time to get ready for a trial.

"We've all been to therapists and have talked to our families and have our support groups, so we're prepared," said Marcus Weaver, who was shot in the arm and whose friend, Rebecca Wingo, died in the attack. "It's gonna be quite the journey."

It could take until June to find the jurors and alternates who were not biased by the widespread news coverage of the shooting. Equally challenging will be finding jurors who were not personally affected by the attack.

Judge Carlos Samour called nearly nine times as many prospective jurors as were summoned in the ongoing Boston marathon bombing trial. That meant the county's 600,000 residents had a nearly one-in-50 chance of being selected.

Among those summoned were 13 people who were either witnesses to the attack or have family members who work in the prosecutor's office. They were quickly excused.

During the selection process, Holmes's attorneys will focus on picking jurors who are morally opposed to capital punishment, even as prosecutors fight to ensure those on the panel are "death-penalty eligible," meaning they would be open to executing Holmes.

"Because of the heinous nature of the crime and the number of victims, I can see people who would say, `In most instances I could not support the death penalty, and in this case, I can."' said Joseph Rice, managing partner of the Jury Research Institute, a California-based trial consulting firm.