AURORA, Colo. – Authorities on Saturday began disarming trip wires and explosive devices "set up to kill" inside the apartment of the suspect in the deadly Colorado movie theater shooting, hoping to find clues to his motive without destroying key evidence in a blast.

Federal authorities detonated one small explosive and disarmed another inside James Holmes' suburban Denver apartment with a device that emits a shock wave and water, a law enforcement official told The Associated Press. The official spoke on condition of anonymity, citing the ongoing investigation into the shooting rampage that killed 12 people and wounded 58.

Holmes' apartment appears to have three types of explosives — jars filled with accelerants, chemicals that would explode when mixed together and more than 30 "improvised grenades," the official said.