Two Bombs

The usual narrative says the two diversionary devices were timed to go off, together, at 11:14. But why lose the complexity of two bombs by having them go off together?

Very curiously, the JeffCo/CNN CD released soon after the massacre says this:
"The examination of the diversionary devices by bomb technicians provided immediate critical information about the sophistication of the devices and the possibility of motion activators attached to the bombs.  That information was relayed to the command post, the SWAT teams and the bomb technicians responding to the scene at the high school."

For one, are they set off by timers or by motion detection?

Impossible to reconcile this unless you understand there were two bombs. The first by timer to cause a fire and divert the first  responders, the second by motion to blow up in the first responders faces. The only other scenario is a bizarre one where you plant a diversion that will never go off unless you are lucky enough for someone to walk by, and somehow knew they would at 11:14.

For two, the police were told they had motion detection? This was "immediate critical information" that was "relayed to the command post"? No wonder the cops did not enter the building. No wonder Sheriff Stone said he did not want to lose men. No wonder it's been said the fire truck they used for cover when retrieving the bodies of Rachel and Richard by the west entrance was also going to be used to breach the west entrance since it could take the brunt of a possible bomb explosion. Supposedly, it got stuck in the mud so they never tried it. Recall also the police had the 911 call in the library, and so could hear the gunmen repeatedly say the library was going to explode.  It was not about "hostages" or protocol for "hostages" being about securing the perimeter. They never tried to negotiate. They had the 911 call to hear the library massacre, meaning they heard this was a murder spree, but also heard them say bombs were about to go off.

The usual narrative says the two cafeteria bombs were timed to go off, together, at 11:17.  The source for this is presumably Eric's notes about the cafeteria being at the fullest at 11:17. However, Dylan wrote down two separate timelines, and one has the bombs going off at 11:16, and the other at 11:17.

Worse, Dave Cullen notes this about the bombs:
"The timing devices were not precise. No digital readouts with seconds counting down in red numerals; they were old-fashioned clocks with a third little alarm hand positioned two-fifths of the way between the 3 and the 4." 

So, you can't "set the bombs to 11:17", (or the diversion for 11:14, presumably) you can only set the bombs to "between 11:15 and 11:20". A far more reasonable explanation for why they began shooting at 11:19 is the bombs were set to explode by 11:20, rather than that they thought both failed at 11:17, and decided in two minutes to have a shooting spree instead, but did not enter the cafeteria where you find the hundreds of victims they wanted dead.

Worse still, they said very clearly the library was going to explode with them inside it, from approximately 11:30 until they left, so they cannot have thought both bombs failed at 11:18.  The cafeteria was below the library and they hoped the bomb in the cafeteria would destroy the pillars holding the library up.

They stop shooting in the library at 11:35, and leave the library at 11:36, then are caught on video trying to set off one of the bombs. They told Bree Pasquale everybody would die from the library exploding whether they shot them or not. They told John Savage to run in order to live. Clearly, everybody in the library was supposed to die. Then, when 11:35 passes, Dylan holds Evan Todd at gunpoint and tell him he is going to let him live. Not he will die anyway from the bombs. Something has changed.

On the Basement Tapes, which are the perpetrators unreleased video messages, but of which there are transcripts, Dylan said "it will be the most nerve racking 15 minutes of my life". What's going to take 15 minutes? Anybody have a better answer than the first bomb at 11:20 and the second bomb at 11:35 supplying the timeline for the massacre? Had the second bomb gone off as they intended, they would have been dead at 11:35.

There is a picture of the bomb they were trying to make explode. The timer is set to 9:35. Surely two hours slow, since all signs point to 11:35, and nothing bomb related was to happen before 11.

The same for the car bombs. Two of them. I'm not sure an official time was released, but a picture of one of the timers has it set to noon, and it's the most common idea for why the perpetrators returned the library around noon before committing suicide, to watch the car bombs explode. I don't have a better idea. I also don't know when the second car bomb was set, but my suspicion is not noon. Perhaps 12:05, since 12:05 to 12:08 is the time of the suicides.