Well fuck, this hits close to home.
When I was in secondary school, one of the scenarios that we had to practice for a drama class wound up being a home invasion, one of the robbers having a gun. Being a bit of an autistic dumbass, I brought in this realistic looking BB gun, modelled after a Colt M1911. Being excited and all, I showed it to some friends behind the back of the Asperger's Resource Centre of the school - usual area we played.
Now, a member of staff spotted me waving this pretty damn realistic looking handgun around in a country where they're outlawed, and told the headteacher. They proceeded to make the judgement call... of telling the ARC's staff, who proceeded to talk to me about how dumb I was being. They mentioned how the firearms police could have been called if someone less familiar with the context of things had seen me. But in the end, they decided to err on the side of caution, and so I didn't get into any further trouble after, while the BB gun was given to the police to be destroyed.
Now, one could apply a number of differing metrics to why I am still here, able to type this:
1) I live in Britain, where gun culture is not so prevalent that a teenager with an actual handgun is somehow plausible.
2) My headteacher used a number of his brain cells to actually consider the context in which I had been spotted, while the staff member who had spotted me didn't automatically assume I was dangerous, possibly because of...
3) I'm white.
I'm sorry to be an armchair analyst from the other side of the Atlantic on this topic, but something is fucked up when a boy that was in a place to get help winds up shot dead. Unfortunately, this is but an extension of a number of increasingly prevalent issues America has with regards to its police forces.