NEW YORK – The vast majority of complaints about New York City police officers' mistreatment of youths stemmed from encounters with black and Hispanic children, according to a new study by the city’s police watchdog agency.Nearly two-thirds of youth complaints to the Civilian Complaint Review Board involved children of color, the report says, including some “stopped for seemingly innocuous activities such as playing, high-fiving, running, carrying backpacks, and jaywalking."The report, based on a review of more than 100 complaints, highlights several instances of racial profiling and comes amid mounting calls for police reforms in the wake of the May 25 death of George Floyd at the hands of Minneapolis police.