He didn't point the bb gun at anyone. He had it to his side. They shot him down.
I'm not sure of the exact requirements of a justified shoot in that state... BUT if their police report said "he pointed it at us", it's a lie.
The caller, who washed out of military in 7 weeks and seemed to have a hard-on here... exaggerated with claims of "he was waving around a gun and pointing it at people". he was not.
Above all, it appears there was never any interaction between police and dead kid. He was facing shelf, playing with an air rifle, hanging by his side, pointing at floor. They saw him and opened fire. No "Police, drop it". That's scary. Could happen to any of US. Caller made up shit about pointing at people. Cops fired without attemping contact. Imagine that happening to any of us... buying a toy rifle, some prick over--reacts, and cops skip the chat part and just open fire. Best of all... the cops won't be charged, it was decided today.