CENTENNIAL, Colo. — An elaborate booby trap system that authorities say was set up to pull police away from the Colorado theater shooting included improvised napalm and thermite, which burns so hot that water can't put out the blaze.
FBI bomb technician Garrett Gumbinner described the system Tuesday at a hearing in which prosecutors laid out their case against suspect James Holmes.
He said three different ignition systems were found in Mr. Holmes' apartment. There was a thermos full of glycerin leaning over a skillet full of another chemical. Flames and sparks are created when they mix, and a trip wire linked the thermos to the door.
Police said Mr. Holmes hoped loud music would lure someone to the apartment.
Prosecutors are trying to show in what is expected to be a weeklong hearing that the attack that killed 12 and wounded dozens July 20 was a premeditated act and that Mr. Holmes should stand trial.
Defense attorneys say their client is mentally ill. Daniel King, one of Mr. Holmes' lawyers, on Monday pointedly asked a pathologist who had just detailed each of the fatalities: "You're aware that people can be found not guilty on the grounds of insanity?"
So far, the pretrial hearing has focused on the horror Aurora police officers discovered at the theater. The magnitude of the attack could be heard in the first 911 call to police, played Tuesday in court. It lasted 27 seconds and police say at least 30 shots could be heard.
The call came in 18 minutes into the showing of "The Dark Knight Rises."
Police also played a 911 call from a teenage cousin of 6-year-old Veronica Moser-Sullivan, the youngest person killed. A dispatcher tried to talk her through CPR but she sounded panicked and said she couldn't hear.
A bearded and disheveled Mr. Holmes stared straight ahead and didn't show any emotion as the calls were played.
Mr. Holmes watched intently as one detective showed a surveillance video of him calmly entering the theater lobby, holding the door open for a couple behind him, and printing out tickets to the midnight showing of "The Dark Knight Rises" that he purchased electronically nearly two weeks earlier. Authorities did not show a video of the attack but say Mr. Holmes, wearing body armor, tossed two gas canisters into the packed theater, then opened fire.
The hearing will be the best opportunity yet for survivors to find out about Mr. Holmes' mental state and the sequence of events that led up to the attack. Mr. Holmes is charged with more than 160 counts, including murder and attempted murder. The hearing will allow the judge to determine whether the prosecution's case is strong enough to warrant a trial, but it's rare for a judge not to order a trial if a case gets this far.