Protests have broken out in New York after a white police officer was cleared of blame over the chokehold death of an unarmed black man stopped on suspicion of selling cigarettes.
The decision by a grand jury not to charge Officer Daniel Pantaleo heightened tensions that have simmered in the city since the death of Eric Garner on July 17.
The videotaped arrest sparked outrage (below) and has drawn comparisons to the shooting in Ferguson, Missouri.
In the neighbourhood where Mr Garner died, people reacted with angry disbelief and chanted: "I can't breathe!" and "Hands up - don't choke!"
Police chiefs met community leaders on Staten Island to head off a repeat of the response in Ferguson, where a grand jury decided last week not to charge the white officer who shot unarmed black teenager Michael Brown.
US president Barack Obama said the Pantaleo grand jury decision underscored the need to strengthen the trust and accountability between communities and police.
The US Justice Department will conduct a investigation into 43-year-old Mr Garner's death.
While not commenting on the decision specifically, Mr Obama said there were "too many instances where people just do not have confidence that folks are being treated fairly".