THE man accused of last year's Colorado cinema massacre used a mobile phone to take self-portraits the night of the attack, sticking out his tongue, smiling and posing with a Glock pistol, prosecutors say.
A judge will rule by Friday on whether James Holmes will stand trial in one of the country's worst mass shootings.
The defence decided not to call witnesses to testify about Holmes' mental health at the hearing on Wednesday.
They have said the 25-year-old is mentally ill and are expected to present an insanity defence.
The July attack left 12 dead and 70 injured. Prosecutors this week have argued that Holmes acted with deliberation and extreme indifference, and on Wednesday showed photos they say Holmes took of himself and his arsenal hours before the attack.
The mobile phone photos include one of Holmes sticking out his tongue. His eyes are narrowed. On either side of his head are curls of red hair protruding up like horns.
Sgt Matthew Fyles testified that Holmes also wore black contact lenses at the time the photo was taken.
In another photo taken that evening, Holmes grins at the camera, with the muzzle of a Glock pistol below his face.
In a third photo, Holmes looks at the camera with pursed lips. He holds one of the black, spherical objects that officials described as a pyrotechnic shell used to rig his apartment for an explosion.
Protruding from top is a red and white-striped fuse, and it appears Holmes is blowing it out as if it were a candle.
Another photo shows Holmes' bed. On it is a tactical vest, .223 calibre magazines, pistol magazines, a gas mask, a Glock in a holster, a ballistic helmet, jacket and pants, an assault rifle, a shotgun, a bag that could be used to carry magazines and a carry-all bag.
Police also showed pictures of the theatre they say Holmes took about a month before the shooting.
The first one, taken on June 29, shows an exit door like the one police say Holmes propped open on the night of the shooting so he could re-enter the theatre after getting weapons from his car.
Fyles testified that a witness saw a man with red hair walk toward the emergency door, apparently on the phone, and propped open the door.
Prosecutor Karen Pearson said Holmes picked the perfect venue for his alleged crime.
"He didn't care who he killed or how many he killed, because he wanted to kill all of them," she said.
Defence lawyers had won unusual permission to call two witnesses during the hearing but changed their minds, saying the rules of the preliminary hearing severely limited what evidence they could present.
If Holmes goes to trial and is convicted, his lawyers can try to avoid a possible death penalty by arguing he is mentally ill. Prosecutors have yet to say whether they would seek the death penalty.
If he's found not guilty by reason of insanity, he would likely be sent to the state mental hospital.
Such a defendant is deemed not guilty because he didn't know right from wrong and is therefore "absolved" of the crime, said former Jefferson County District Attorney Scott Storey.