A man killed his girlfriend in Baltimore and then traveled to New York and killed two cops and himself. His instagram account strongly implies that these were revenge killings for the deaths of Eric Garner and Michael Brown.
This is especially not good because NYC Cops are angry that Mayor De Blasio criticized the Grand Jury decision in the Eric Garner case.
Update: The girlfriend was only shot, not murdered. When I wrote this post, reports were saying she was murdered.