Just comparing the basic facts from Columbine and Sandy Hook...
Columbine: shooting starts at 11:19am, and they commit suicide at 12:08pm. There were two shooters, with a 2 rifles (TEC-9, HiPoint 995), 2 shotguns, 4 knives, and 99 explosives. SWAT enters at 1:09pm. Medical help is allowed to enter at 3:03pm. Results: 15 dead, 24 injured. 188 rounds fired (67 by Klebold, 121 by Harris).
Sandy Hook: First shot (to enter the building) was at 9:35am. Last shot (suicide) was at 9:40am. One shooter. 3 firearms. Police enter at 9:44am. Medical help enters at 9:51am. Results: 27 dead, 2 injured. 157 rounds fired (154 from the Bushmaster XM15 rifle, 2 from the 10mm Glock, and 1 suicide shot from the Sig 9mm)
Immediate questions raised:
1. How does 1 shooter kill 27 in 5 minutes, with a 93% fatality rate... when 2 shooters fire more rounds, over 49 minutes, kill only 15 and only have a 38% fatality rate?
2. How can the vast disparity in mortality rates be explained when medical help was delayed for 2:55 at Columbine, and was delayed for only 6 minutes at Sandy Hook? Medics were treating victims within 16 minutes of the first shot being fired... and yet couldn't save more than 7% of the victims? And the Columbine medics were delayed for 3 hours, and they were able to save 62%???
3. How does 1 shooter, who starts firing outside the building (to gain entry), get off 157 rounds so accurately so quickly (averaging one shot every 2 seconds)... when the more deliberate pair at Columbine is far less deadly, with ten times as much time to operate (averaging one shot every 16 seconds, plus talking to intended victims)?
These disparities alone are enough to make one wonder. These are the facts directly from the police reports, and the differences are stark.
You do realize that people who truly believe the Apollo Moon landings were faked and the ones who believe the Earth is flat can also lay out their own rationale and reasoning for their beliefs? You’ll find the same thing at play with Scientologists and other cult groups.
The problem is when a person has already decided something “is so” they will tend to look only for facts/beliefs that fit the pre-decided end-concept rather than rejecting the concept itself.