Don't know much about Sandyhook shooting. Just that a nutty maladjusted mama's boy shot Mom and then went to an unguarded school and shot the place up. But the Las Vegas shooting had to have happened. There were thousands there to deny it. Now as to the shooter and whether there were others involved, that's a fair question. I don't believe in the humans walking on the moon story but it would be impossible to get by with something on earth among a well populated area with thousands of witnesses. The only questions are motive and accomplices. Sometimes motive just boils down to crazy which is very hard to defend against. Can't lock up crazies anymore. As an old colored man once told me "theys a heap o' people crankin off these days". I think he meant cracking up.
