CENTENNIAL, Colo. (CBSNewYork/AP) -- Looking dazed with his hair dyed red, James Holmes, the man accused of opening fire inside a Colorado moving theater during a midnight showing of the new Batman movie "The Dark Knight Rises," made his first court appearance on Monday.
It came as police continue to analyze evidence from the theater and suspect's apartment as they work to understand his mindset and motivation.
Video from the inside the courtroom showed Holmes with reddish-orange hair. He was seated in the jury box, often looking down and closing his eyes while showing little emotion. He looked dazed as Judge William Sylvester advised him of the case.
PHOTOS: Colorado Theater Massacre
Holmes has been in solitary confinement since Friday when the 24-year-old, clad in body armor and armed with an assault rifle, a shotgun and handguns, shot and killed 12 people and injured 58 more inside an Aurora movie theater, police said.
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 and said it will be months before a decision is made.
Friends and family members of some of the victims were also in court, including the father of shooting victim Alex Teves, who sat in the front row with his eyes fixed on Holmes.
Holmes is being held on suspicion of first-degree murder and he could also face additional counts of aggravated assault and weapons violations. He will be formally charged next Monday.
COULD SHOOTING HAVE BEEN MORE DEVASTATING?
While Holmes looked more sleepy than sinister on Monday, police said his crime was meticulously planned and carefully executed.
But some believe a few unforeseen details probably prevented additional deaths and the suspect's possible escape. Holmes reportedly outfitted his AR-15 rifle with a high-capacity drum. But the ammo drum jammed, forcing Holmes to turn to handguns, CBS 2's Tony Aiello reported.
Because of that brief delay, one witness said, there was some time to escape.
"There was a time of quietness, and so everyone started bolting for the exit at the top," said witness Tanner Coon.
As for his escape, Holmes was dressed in black ballistics gear similar to that worn by the Aurora Police Department SWAT. Police said it's possible he hoped to blend into the crowd of first responders.
"In that chaos, it is quite reasonable that an officer might have confused him for another SWAT officer or heavily armed officer responding to the scene," said Aurora Police Chief Dan Oates.
But two eagle-eyed cops noticed something irregular about Holmes' equipment and called for backup.
The search warrant for Holmes' apartment was sealed by a judge Monday, but one source said a batman mask was among the material recovered, including computers.
MAYOR BLOOMBERG CALLS FOR GUN CONTROL
As new details about the suspect and the investigation continue to trickle out, New York City Mayor Michael Bloomberg is again calling on presidential candidates to come up with a specific plan on gun control.
Bloomberg said Monday in the next presidential term, 48,000 people will have been killed by illegal guns.
WCBS 880's Rich Lamb: Bloomberg Keeps On Obama, Romney On Guns
"It seems to me not unreasonable that whoever wants to be president should tell us what they're going to do about it before we go to the ballot box," the mayor said.
Bloomberg said it is incumbent on President Barack Obama and GOP candidate Mitt Romney to address the issue "specifically, not in just broad terms.''
He said some people feel it's insensitive to talk about gun control as the nation mourns Colorado's victims. But he asked: "If not now, when?''
INVESTIGATORS STILL PUTTING TOGETHER PIECES
Police have said that 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.
"I think it speaks volumes about his intelligence and his deliberation and his cold-bloodedness," Aurora Police Chief Dan Oates said. "I could not believe the pictures I saw from the robot about the way this thing was designed. And there was a second triggering mechanism, too."
Investigators still are piecing together a chilling trail of warning signs.
On his Adult Friend Finder profile, Holmes asks potential partners "Will you visit me in prison?"
A month ago, he applied online to a Colorado gun range.
When the owner called back to conduct a phone interview, he said he was struck by the voice mail greeting, describing it as "bizarre, guttural, freakish at best."
Tactical teams spent the weekend dismantling an arsenal of explosives inside Holmes' apartment which was rigged with trip wires and designed to set off a massive explosion, police said.
Investigators said they found a Batman mask inside Holmes' booby-trapped apartment after the attack.
NYPD Police Commissioner Ray Kelly said Friday that he was told at the time of the shooting that Holmes "said he was 'The Joker,' obviously the 'enemy' of Batman."
On Sunday, 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 school officials weren't saying whether they knew he was anything more than a hard-working student.
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 with President Barack Obama arriving to visit with families of the
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.
Several thousand gathered for healing at the vigil Sunday night, where a banner said, "Angels Walk With Those Who Grieve.''
'BATMAN' STARS ADDRESS THE TRAGEDY
Meanwhile, the stars of the "Dark Knight Rises" are speaking out.
Anne Hathaway, who plays Catwoman, released a statement saying: "My heart aches and breaks for the lives taken and altered by this unfathomably senseless act. I am at a loss for words how to express my sorrow. My thoughts and prayers are with the victims and their families."
Christian Bale who plays Batman said: "Words cannot express the horror that I feel. I cannot begin to truly understand the pain and grief of the victims and their loved ones, but my heart goes out to them."
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