It is always diffcult to judge from newspaper reports but ....Britain, UK news from The Times and The Sunday Times - Times Online: "The father of three from Hackney, East London, was shot in the head and hand on September 22, 1999 after a table leg he was carrying in a blue plastic bag was mistaken for a sawn-off shotgun." (My emphasis)
"The CPS has concluded that the prosecution evidence is insufficient to rebut the officers’ assertion that they were acting in self defence. We have also concluded that the threat which they believed they faced made the use of fatal force reasonable in the circumstances as they perceived them."(My emphasis)
So in the UK, don't where quilted jackets(oh wait, I mean don't wear be Brazilian and where a denim jacket), don't carry things in plastic bags......
I think a large part of the problem is that, since they are normally deal with criminals, the police lose sight of the fact that most people are just going about there normal business.