There is no doubt this was a mistake, but given all the factors; call to the scene (someone else felt threatened or perceived such), bad violent neighborhood (the helicopters hover over it every night without anyone shot), gang colors, non-compliant, realistic toy weapon, I tend to side with reasonable mistake. The deputy knew the neighborhood. I do not perceive him as trigger happy.
You’ll notice that I’m not calling for the officer’s head. I do think we need to look beyond the incident, though. Bad welfare policies, bad gun control policies, bad drug control policies, and bad border control policies have created an environment conducive to this and similar mistakes. The officer shot an unarmed kid, the unarmed kid was a junior thug pretending to be armed, the surrounding society is sick and broken in myriad ways, as a (perhaps unwitting) result of incredible stupidity and evil in government and amongst the denizens of ‘bad neighborhoods’. It’s a hideous mess.