"He intended to kill them all," prosecutor in theater shooting says NEW: Theater shooting suspect chose his venue carefully to maximize death, prosecutor says James Holmes "didn't care who he killed," prosecutor says NEW: Judge to rule on Friday whether case can proceed to trial NEW: Defense declines to put on its own case Centennial, Colorado (CNN) -- Two weeks before a bloody shooting rampage that killed 12 people at an Aurora, Colorado, movie theater, suspect James Holmes apparently visited the cinema and took photographs of hallways and doors, a police detective testified on Wednesday. Holmes returned nine days before the massacre, Sgt. Matthew Fyles testified at the the conclusion of a preliminary court hearing, and took pictures of exterior doors. The photographs were recovered from Holmes' cell phone and go along with months of sales records and descriptions of meticulously prepared booby traps at his home. It all helps illustrate what would appear to be a well-planned attack. "He didn't care who he killed," prosecutor Karen Pearson told the judge at the conclusion of her case against Holmes, saying he chose his venue carefully to cage his victims. He intended to kill them all. Read more: New details emerge at hearing The former neuroscience graduate student is charged with 166 counts of murder, attempted murder and weapons violations in the July 20 shooting that killed 12 and wounded 58. Arapahoe County District Judge William Sylvester said he would rule on Friday whether authorities presented enough evidence during the three-day hearing to proceed to trial. Defense attorneys, who had been expected to call witnesses and argue a "diminished capacity" defense, changed their minds during the hearing, attorney Dan King said. "We have had a change of position," he said. This is neither the proper venue nor the time to put on a show or present some truncated defense. Before wrapping up, prosecutors asked Fyles to display other photos taken from Holmes' phone, including shots of improvised explosives under construction in his kitchen on July 16 and disturbing images of the suspect, his read hear curling out from beneath the black watch cap prosecutors say he wore to the theater. In one image, he is sticking out his tongue and wearing contact lenses that render his eyes utterly black. In another, he holds a firework that resembles the spherical bombs so prevalent in cartoons. He appears to be whistling in the photo. The pictures were taken July 19, the same day authorities say Holmes headed to the theater to begin his rampage shortly after midnight on July 20. Holmes could be seen smiling slightly as the photographs were displayed. According to hearing testimony, here is what is known about his alleged preparations: Holmes began buying guns in May, supervisory agent Steve Beggs of the Bureau of Alcohol, Tobacco, Firearms and Explosives testified on Tuesday. Beggs said he built an arsenal of two Glock handguns, an AR-15 rifle, a shotgun and 6,295 rounds of ammunition. Among other purchases, Beggs said Holmes bought two six-ounce tear gas grenades over the Internet on May 10 and he went to a gun store on May 22 to buy one of his Glocks. A little more than a month later, on July 1, a video camera captured Holmes as he bought a scope, a mount and some inert ammunition at a Colorado gun store, Beggs said. Four days later -- July 5 -- Holmes apparently visited the theater and used his iPhone to take pictures of interior doorways, Fyles testified On July 7, Holmes used an online ticketing service to buy a ticket for the midnight showing of the movie, according to Detective Craig Appel, the lead investigator in the case. He then returned to the theater two days later to take pictures of exterior doorways, Fyles testified. Read more: Remembering the victims At least some of the preparations were well under way by July 16, based on a photograph from Holmes' phone shown by prosecutors. In it, jars, wires, firework shells and other bomb-making materials are laid out in his kitchen. By the time Holmes left, the carpet in his apartment had been soaked in oil and gas, FBI bomb technician Garrett Gumbinner testified. A series of disturbing self portraits displayed in court, apparently made sometime before Holmes allegedly left for the theater, according to data retrieved from his phone, show him in the eye-blackening contacts, his tongue stuck out in one, flashing a toothy grin and a handgun in another. At some point, according to Pearson, one of Holmes' weapons jammed. "Had the AR-15 not jammed, he would have killed more people," she said. Police also found one of the tear-gas canisters inside the theater, Appel said. Also located was a large drum magazine for the rifle that appeared to have jammed, Sgt. Gerald Jonsgaard testified Monday. Prosecutors are expected to finish their presentation on Wednesday, followed possibly by defense witnesses. Read more: University releases e-mails related to Colorado theater shooting suspect