If the shooter went thru the trouble to do all the booby traps, why do you suppose he notified the police that he had bombs in his apartment? Why not just let them go there and find it themselves and get blown up?
Presumably he set this up to allow him more time to allegedly kill people in the movie theater, but that didn't work. Since it didn't work for what he allegedly planned it for, perhaps he didn't care for it anymore.
"Investigators now believe that Holmes used a timer to set off loud techno music at the apartment just before midnight. It was meant to spur a noise complaint to police. The ruse theoretically would have drawn them into the apartment building, detonating a firebomb and then drawing all available police and rescue units to the other side of town before the shooting at the theater started. That would have allowed him more time to kill more people and left a much smaller police response to the theater shootings."
http://www.cbsnews.com/8301-18563_1...p-elaborate-bomb-in-apartment-as-distraction/