Another mass murder in Colorado

An horrendous act of mass murder was committed in Aurora at the premier last night of the new Batman movie by a white guy with no previous criminal charges. What are his thought processes? "I get to do whatever I want to do, and nobody else matters?" No prior models. What happened? Anamoly? Grudge?

Update: Killer is 23. Came into theater with four weapons and threw tear gas, then just started murdering people. Was wearing black, bullet proof vest.

Update 2: The killer's mother lives in San Diego. She is on her way to Colorado, and purportedly told the police, "You've got the right man." James Holmes is in custody. Only prior is a traffic incident. Was wearing a black mask, and black outfit when he kicked in the emergency exit door, threw something like tear gas, and started shooting.

Update 3: Police and F.B.I. say that the entire apartment building where the guy lived is booby-trapped from the inside.

Update 4: My first four paragraphs were written early this morning.I have now gone to work and returned home. Here are some additions and corrections. Radio news says Holmes is not talking, not cooperating with police. Twelve people are dead. 59 more are injured from his gunfire.

Police have not decided what to do about the booby-trapped apartment. Apparently it is the apartment, not the whole building, that is booby-trapped. Five buildings have been evacuated.

Killer is 24. He was wearing armored ballistic protection all over his body and a gas mask. He purchased a ticket, then went out the back exit, went to his car to get the weapons, came back in the back door, and threw tear gas or some kind of gas into the crowded theater after the movie started, and opened fire as people tried to escape the tear gas and shooting.

Holmes graduated with bachelors degree from the U. of  California in Riverside. Graduated with highest honors. Currently a PhD candidate at U. of Colorado Medical School in Neuroscience, but had started the process of dropping out of the program.

What about the victims? Will we learn anything about them? Or is this just about Holmes?

Update 5: Earlier in the night, before the movie premier, loud "techno-music" was playing in the Holmes apartment on the third floor of the apartment building. The person who lived below his apartment called the police. They could not respond, because they were dealing with other calls. If they would have responded, they would have found an apartment that was trip-wired with explosives.

Update 6: Killer's father also cooperating with police.