By P.SOLOMON BANDA and NICHOLAS RICCARDI
CENTENNIAL, Colo. (AP) -- As the suspected gunman in the Colorado theater massacre heads to his first court appearance Monday, authorities have disclosed that he is refusing to cooperate and that it could take months to learn what prompted the horrific attack on midnight moviegoers at a Batman film premiere.
James Holmes has been held in solitary confinement at an Arapahoe County detention facility since Friday but will be moved to a nearby courtroom for a 9:30 a.m. MDT hearing, where he will hear the pending charges against him. Holmes is being held on suspicion of first-degree murder, and he could also face additional counts of aggravated assault and weapons violations.
Prosecutors will have 72 hours from the hearing to formally charge the 24-year-old Aurora resident originally from California.
Eighteenth Judicial District Attorney Carol Chambers said Monday her office is considering pursuing the death penalty against Holmes. She said a decision will be made in consultation with victims' families.
Holmes has been assigned a public defender, and Aurora Police Chief Dan Oates said the former doctoral student has "lawyered up" since his arrest early Friday, following the shooting at an Aurora theater that left 12 dead and 58 wounded, some critically.
"He's not talking to us," the chief said.
Holmes has been held without bond at the lockup in Centennial, Colo., south of Denver and about 13 miles from the Aurora theater.
His hearing is at the same complex, and security there was tight early Monday. Uniformed sheriff's deputies were stationed outside, and deputies were positioned on the roofs of both court buildings at the Arapahoe County Justice Center.
Police have said Holmes began buying guns at Denver-area stores nearly two months before Friday's shooting and that he received at least 50 packages in four months at his home and at school.
Holmes' apartment was filled with trip wires, explosive devices and unknown liquids, requiring police, FBI officials and bomb squad technicians to evacuate surrounding buildings while spending most of Saturday disabling the booby traps.
Investigators found a Batman mask inside Holmes' apartment after they finished clearing the home, a law enforcement official close to the investigation said Sunday on condition of anonymity because he was not authorized to speak to the news media.
Officials at the University of Colorado Anschutz Medical Campus were looking into whether Holmes used his position in a graduate program to collect hazardous materials, but that disclosure was one of the few it has made three days after the massacre. It remained unclear whether Holmes' professors and other students at his 35-student Ph.D. program noticed anything unusual about his behavior.
His reasons for quitting the program in June also remained a mystery. Holmes recently took an intense oral exam that marks the end of the first year. University officials would not say if he passed, citing privacy concerns.
Amid the continuing investigation of Holmes and his background, Sunday was a day for healing and remembrance in Aurora, with the community holding a prayer vigil and President Barack Obama arriving to visit with families of the victims.
Obama said he told the families that "all of America and much of the world is thinking about them." He met with them at the University of Colorado Hospital in Aurora, which treated 23 of the people injured in the mass shooting; 10 remain there, seven hurt critically.
Congregations across Colorado prayed for the shooting victims and their relatives. Elderly churchgoers at an aging Presbyterian church within walking distance near Holmes' apartment joined in prayer, though none had ever met him.
Several thousand gathered for healing at the vigil Sunday night.
"You're not alone, and you will get through it," said the Rev. Kenneth Berve, pastor at Grant Avenue United Methodist Church and a witness to Friday's horrors. "We can't let fear and anger take control of us."
Meanwhile, the owner of a gun range told the AP that Holmes applied to join the club last month but never became a member because of his behavior and a "bizarre" message on his voicemail.
Holmes emailed an application to join the Lead Valley Range in Byers on June 25 in which he said he was not a user of illegal drugs or a convicted felon, said owner Glenn Rotkovich. When Rotkovich called to invite him to a mandatory orientation the following week, Rotkovich said he heard a message on Holmes' voicemail that was "bizarre _ guttural, freakish at best."
Rotkovich left two other messages but eventually told his staff to watch out for Holmes at the July 1 orientation and not to accept him into the club, Rotkovich said.
The pastor for the suspect's family recalled a shy boy who was driven to succeed academically.
"He wasn't an extrovert at all. If there was any conversation, it would be because I initiated it, not because he did," said Jerald Borgie, senior pastor of Penasquitos Lutheran Church. Borgie said he never saw the suspect mingle with others his age at church. He last spoke with Holmes about six years ago.
"He had some goals. He wanted to succeed, he wanted to go out, and he wanted to be the best," Borgie said. "He took pride in his academic abilities. A good student. He didn't brag about it."
During the attack early Friday, Holmes allegedly set off gas canisters and used a semiautomatic rifle, a shotgun and a pistol to open fire on theater-goers, Oates said. Holmes had bought the weapons at local gun stores in the past two months. He recently bought 6,000 rounds of ammunition over the Internet, the chief said.
The gunman's semiautomatic assault rifle jammed during the attack, forcing him to switch to another gun with less firepower, a federal law enforcement official told The Associated Press. That malfunction and weapons switch might have saved some lives.
Oates said a 100-round ammunition drum was found in the theater, but he said he didn't know whether it jammed or emptied.
The shooting was the worst in the U.S. since the Nov. 5, 2009, attack at Fort Hood, Texas. An Army psychiatrist was charged with killing 13 soldiers and civilians and wounding more than two dozen others.
Associated Press writers Kristen Wyatt and Thomas Peipert in Aurora; Dan Elliott, Gillian Flaccus and Colleen Slevin in Denver; and Alicia A. Caldwell, Eileen Sullivan and Julie Pace in Washington contributed to this report.