Peeping Inside A Deranged Mind
These are my hunches; investigators are yet to verify them as facts.
Reported phone call
Many have reported that JH received a phone call which he apparently went out to answer before he returned for what is now part of a sad history. I tend to believe JH received no phone call from any one or party. More likely, he was responding to a timed phone alert he preset for himself. That alert was likely to have been synchronized with the onset of the loud and recurring music in his apartment. It would be interesting to check the timing of JH's phone ringing in the theater with the start of the loud music in his apartment.
Loud music a ploy to detract attention and task police manpower deployment
Colorado Police Chief Oates' claim that the incendiary devise in JH's apartment was designed to kill first responders breaching JH's space might be correct. My theory is that, additionally, JH might have intended to divert the attention of the police, confuse the force into thinking this might be a wider chain of terror events unfolding, and thus task police manpower deployment to his primary 'theater of war.' The suspect spent the interval between the simultaneous onset of the music in his apartment and his preset phone alert to temporarily exit the theater and suit up for count zero.
If JH's apartment had been breached either by an angry neighbor (as it almost happened) or some officers responded to a nuisance call and triggered the devises, the resulting melee would have meant the police dispatching a detachment to that scene and correspondingly depleting manpower available to respond to the shootings at the theater.
Bear in mind that if the police thought this might be more widespread, it could have had to make preemptive deployments to other sensitive locations, further stretching available manpower. As such, JH's primary goal might be to divert attention from the theater shooting (if only for some time) and gain additional leverage. The police chief's claim that the incendiary devises were intended to kill, while credible, might be of secondary consideration to JH. Acting under his overdosed Vicodin-induced calmness, the moment he knew the game was up, JH surrendered to the police without resistance and even warned that his apartment was rigged. His deranged mind might be rationalizing that disclosing this to the police when he did would buy him some later reprieve or mitigation (remember there may come a time for allocutus). He might also be playing to further muddle up the already mixed signals and lend further credence to these sad events being the product of a deranged mind; grounds for a likely plea of insanity (McNaughton Rule).
We need as much intelligence as possible from forensic examination of JH's cell phone, the music box in his apartment, other tools, and any debriefing that his attorneys would allow. These would help plan proactively against future occurrence of these types of sad events. Yes, evil may manifest despite abundance of caution; we still have options to simply throwing up our hands in helpless surrender.