The answer to the LEOs caution in seeking access to Holmes' apartment.
Richard 
Updates from hearing: Holmes said to have rigged home with explosives to distract police
A federal agent testified Tuesday
(8 Jan 2013) that James Holmes, who is charged in the Aurora, Colo., theater massacre, had booby-trapped his apartment and intended it to serve as a distraction while he went on his shooting rampage.
FBI bomb tech Garrett Gumbinner testified that Holmes used
improvised napalm, homemade thermite, gasoline, smokeless gun powder, rifle bullets and a host of wiring and electronics to rig more than a dozen explosives and incendiary devices.
Holmes told the agent that he hoped to draw his neighbors and police to the elaborate system by setting up music to be played loudly from his home computer or a boom box he placed near a dumpster outside his apartment.
Above the boom box was a remote-controlled toy car and what looked like a remote control, but was in actuality a controller used in fireworks shows. It would have set off the explosives inside the apartment.
Meanwhile,
fishing line tied to the apartment door would also have set off the explosives.
The testimony came during the second day of a preliminary hearing to determine if Holmes should stand trial for the shooting deaths of 12 people and for charges that he wounded numerous other people in the attack.