For anyone from abroad here a short collection of some of the most tragic incidents:
=> July 2014: Eric Garner died after being put in a chokehold by the police on the sidewalk outside a shop in Staten Island/NY
https://en.wikipedia.org/wiki/Death_of_Eric_Garner
=> November 2014: Tamir Rice, the 12-year-old boy playing with a toy gun in a park in Cleveland, was shot dead by a police officer.
https://en.wikipedia.org/wiki/Shooting_of_Tamir_Rice
=> August 2014: Michael Brown was killed by a police officer in Ferguson, Missouri
The shooting of Michael Brown occurred on August 9, 2014, in Ferguson, Missouri, a suburb of St. Louis. Brown, an 18-year-old black man, was fatally shot by Darren Wilson, 28, a white Ferguson police officer.
https://en.wikipedia.org/wiki/Shooting_of_Michael_Brown
=> Walter Scott was killed by the police in South Carolina
http://www.msnbc.com/msnbc/reporters-notebook-the-killing-walter-scott