Holmes also bought two Glock handguns, a shotgun and an AR-15 rifle, along with 6,295 rounds of ammunition, targets, body armor and chemicals, prosecutors said. The magnitude of the attack was captured in the first 911 call, played Tuesday in court, that police said recorded at least 30 shots in 27 seconds.
He dyed his hair bright orange, then bought a scope and non-firing dummy bullets on July 1, the visit and the new hair color documented in security video.
Finally, he purchased glycerin and potassium permanganate — chemicals that could combine to create fire and sparks — from a Denver science store. At some point, he also improvised napalm, as well as thermite, a substance which burns so hot that water can't extinguish the blaze.
Holmes' purchases were split between two planned attacks, prosecutors said — the theater shooting and a booby trapped apartment that would've blown up if anyone had entered.
The bottle of glycerin was meant to fall into the permanganate when the door to his apartment opened, to cause an explosion and then a fire, prosecutors said.
Parts of Holmes' carpet were soaked with gasoline and oil and ammonium chloride, a white powder, was poured onto the floor in strips, FBI bomb technician Garrett Gumbinner said.
"It would have ignited and the whole apartment would have exploded or caught fire," Gumbinner said.
He said the system had two other initiating systems. One was a pyrotechnics firing box that would have been triggered by the remote control unit of a toy car left along with a boom box set to play loud music. Gumbinner said Holmes told him he hoped the music would lure someone and lead them to play with the car, thereby detonating the explosives.
The other initiating system was a model rocket launch box which operated by means of infrared light, but Holmes told investigators it wasn't armed, Gumbinner said.