Apparently there is a kernel of truth to this
https://www.yahoo.com/news/brazil-sends-troops-state-torn-violence-due-police-183009012.html
http://www.dailymail.co.uk/news/article-4195318/Thugs-randomly-shooting-passes.html
The only other reference that I have seen was small article on Drudge .
Reuters has a story too
and the Daily Mirror has a brief one but with awful pictures.
WOW.