SHAFAQNA (International Shia News Association) New York’s attorney general has asked the governor for the power to investigate and prosecute local police killings of unarmed civilians.
Eric Schneiderman said independent reviews of such cases would “restore trust” in the justice system.
Meanwhile, the family of an Ohio boy, 12, killed by police last month have called for the officer to face trial.
Protests against police killings of unarmed black men continued on Sunday, but turned violent in California.
Others demonstrations, including in Miami, Minneapolis, Philadelphia and New York City, were peaceful.
Protesters have been angered by the deaths, including those of Eric Garner, killed in a chokehold in New York, and Michael Brown, who was shot dead by a police officer in Ferguson.
In both cases grand juries decided not to press criminal charges against the white police officers responsible.
“The horrible events surrounding the death of Eric Garner have revealed a deep crisis of confidence in some of the fundamental elements of our criminal justice system,” Mr Schneiderman said in a statement.
The New York attorney general has asked Governor Cuomo to sign an executive order putting his office in charge of investigating such deaths.
“A common thread in many of these cases is the belief of the victim’s family and others that the investigation of the death, and the decision whether to prosecute, have been improperly and unfairly influenced by the close working relationship between the county district attorney and the police officers he or she works with and depends on every day,” the statement continued.
Mr Schneiderman said he had no doubt that the “overwhelming majority” of local prosecutors are “conscientious about our ethical duty to see that justice is done in every case” but said it was a matter of public confidence.
Also on Monday, US Attorney General Eric Holder announced new guidelines banning law enforcement from racial profiling – the use by police of race as a factor in their decisions.
The protocol, which updates a previous version of the guidelines, will require federal agencies to provide training and collect data on profiling complaints.
The mother of 12-year-old Tamir Rice, who was shot and killed on 22 November by a Cleveland, Ohio, police officer, spoke publicly for the first time on Monday.
Samaria Rice said her son, Tamir, was a “bright child” with a “promising future” who helped out at school.
Rice, who was holding a toy gun, was shot twice and later died in hospital.
Police had responded to an emergency call about someone with a gun near a playground. CCTV video of the area released by police shows Tamir was shot within seconds of a police vehicle stopping nearby.
A lawyer for the family was “very distrustful” of local authorities’ ability to bring charges against police. Ms Rice said she would like to see the officer convicted for her son’s death.
Protests against police killings continued on Sunday, although a peaceful march from Berkeley towards neighbouring Oakland turned violent during the evening.
Some started vandalising local businesses, smashing shop windows, lobbing bottles and setting dustbins on fire.
One person was hit with a hammer in Berkeley trying to stop another protestor vandalising a shop.
In Oakland, demonstrators flooded a highway, throwing rocks at police who responded with tear gas.
Protesters on the highway at Oakland tried to set a patrol vehicle on fire, according to the California Highway police.
Five people were arrested in connection with the demonstrations and two officers were injured.