Amnesty International condemned the "use of excessive force" by police.
An inquiry will be carried out later in to any reports of use of excessive force".
Rights groups have repeatedly condemned the use of excessive police violence during the protests.
He vowed to pursue "targeted measures against those responsible for violence and use of excessive force".
Figures supplied by Chief Wiles suggest that dismissals from the department for use of excessive force were rare.
Black residents have long accused the police of racial profiling, harassment and routine use of excessive force.
(In April, he filed a lawsuit against five New York police officers for false arrest and use of excessive force).
Mr. Abdel Hamid said he argued against the use of excessive force and was then pushed aside.
Civil suits by prisoners seeking monetary damages for the use of excessive force continued for years afterward.
Amnesty International criticised the use of excessive use of force by police, and blamed Mr Erdogan for inciting protesters.
The United States attorney's office is also looking into accusations of use of excessive force, planting evidence and conspiracies to conceal officers' actions.
