An elaborate booby trap system found in the apartment of the suspected gunman in the Colorado cinema shooting included improvised napalm and thermite, which burns so hot that water can't put out the blaze, an FBI bomb technician has testified.
Prosecutors are trying to show that the shooting that killed 12 and wounded at least 58 was a premeditated act and that James Holmes should stand trial for one of the country's worst mass shootings. Defence lawyers have said Holmes is mentally ill.
PHOTOS: Victims of the Colorado shooting
PHOTOS: US Colorado shooting funeral
Bearded and dishevelled, Holmes appeared blank on Tuesday as audio from the first emergency call from the movie theatre was played. The call lasted 27 seconds, and police say at least 30 shots could be heard.
Bomb technician Garrett Gumbinner said three different ignition systems were later found in Holmes' apartment: a thermos full of glycerin leaned 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.
Holmes is charged with more than 160 counts, including murder and attempted murder.
Authorities said the victims who died were shot from one to nine times.
Dozens of survivors and family members of the dead have packed the courtroom as details of the attack, until then kept quiet by a judge's order, emerge.
Later in testimony on Tuesday, Detective Craig Appel said that Holmes had paper bags over his hands to preserve gunshot residue and had played with the bags as if they were puppets.
Appel said Holmes also played with a cup on the table and tried to jam a staple into an electrical outlet.
Defence lawyer Daniel King asked whether Holmes had been tested for drugs or other substances and Appel said there was no indication that he was under the influence of anything.
Appel acknowledged that Holmes's pupils were dilated, something that had also been noted by the officer who arrested him.
On Monday, police officers struggled to hold back tears during their testimony, describing how they found a six-year-old girl without a pulse, tried to keep a wounded man from jumping out of a moving police car to go back for his young daughter and screaming at a gunshot victim not to die.
Holmes watched intently as one detective showed surveillance video of him calmly entering the theatre lobby, holding the door open for a couple behind him, and printing out tickets to the midnight showing of "The Dark Knight Rises."
Authorities did not show video of the attack, but said Holmes, wearing body armour, tossed two gas canisters into the packed theatre and opened fire.
It's rare for a judge not to order a trial if a case gets this far.
Legal analysts say that evidence appears to be so strong that Holmes may well accept a plea agreement before trial, which could result in him receiving a lesser sentence, such as life in prison, if prosecutors decide to seek the death penalty.
It also would help the state avoid a costly trial and spare survivors and families of those who died from the trauma of going through a lengthy trial.