It looks like booby traps along with IEDs, trip wires and accelerants with trigger mechanisms weren't the only things police found in James Holmes' Aurora, Colo., apartment.
A law enforcement official close to the case said today that the 24-year-old suspect's home was also decorated with Batman items, according to the Los Angeles Times.
Investigators said they "found a Batman poster on a wall, a Batman mask and other Batman paraphernalia," in Holmes' 850-square-foot apartment. (Earlier, law-enforcement sources confirmed to E! News that Holmes told police he "was the Joker" upon his arrest.)
Bomb experts and law-enforcement authorities entered Holmes' place Saturday morning in an attempt to defuse various complicated incendiary devices inside that were "set up to kill," police said.
Officials said the design and placement of the hazards "seemed to mirror a chaotic state of mind. There was a level of sophistication to it all. It will be interesting to see what a post-mortem forensic analysis determines regarding the chemicals, powders and devices rigged up in there, and whether the firing train would have actually functioned."
Police have reportedly finished the processing and collecting of evidence from inside Holmes' apartment, but chemical hazards remain, according to the Times.
Holmes is reportedly due to appear in court for his arraignment tomorrow morning.
(Originally published July 22, 2012, at 5:17 p.m. PT)