Three prospective jurors were using their cellphones on Tuesday despite a judge's order, one might have been asleep, and all of them endured a slow security screening as the long slog toward picking a jury in the Colorado theater shooting trial got underway.

It could take until June to seat jurors and alternates for the trial of James Holmes, who is charged with multiple counts of murder and attempted murder in the July 2012 attack on a suburban Denver theater.

The attack killed 12 people and injured 70. Holmes pleaded not guilty by reason of insanity. Prosecutors are seeking the death penalty.

Defense attorneys acknowledge Holmes was the gunman in the attack but say he was in the grip of a psychotic episode at the time.

In initial court appearances after the shooting, Holmes wore an orange jail jumpsuit and a dazed look, but he appeared more conventional Tuesday in khaki slacks, dress shirt and blue blazer. His hair, now a dark brown, was neatly trimmed, and he wore a curly, medium-length beard.

No restraints were visible, though the judge had ordered him to be tethered to the floor in a way the public could not see.

Court officials initially summoned 9,000 prospective jurors, but that figure fell to about 7,000 after some summonses could not be delivered and some people were excused. Seven more were dismissed Tuesday for various reasons.

It took deputies about an hour to screen and search the first wave of about 130 prospective jurors who reported Tuesday. Officials said more deputies would be added Wednesday to speed the process.

The jury candidates heard instructions from the judge and began filling out surveys with 77 questions.

No action was taken against the jurors who used phones or the one suspected of sleeping.