Source- They also released pictures of the aftermath of the shooting and the car Holmes used to drive to the cinema in July 2012.
Holmes killed 12 people and wounded 70 others in the attack.
Last month jurors decided not to give him the death penalty. He was instead sentenced to life in prison without the possibility of parole.
The photos show chemical and incendiary devices linked by wires, intended to distract emergency responders from the cinema shooting. The devices were later defused by a police bomb squad.
Prosecutors said that the traps were designed to kill anyone who tried to enter and that if the explosives had been detonated, the resulting fireball could have damaged much of the building.
The images were released after open records requests.
Holmes slipped into a midnight screening of Batman film The Dark Knight Rises armed with a semi-automatic rifle, a shotgun and a pistol.
He threw smoke canisters and shot at people trying to escape.
Prosecutors argued the attack was clearly premeditated, with Holmes planning and amassing weapons for months.