WASHINGTON — U.S. Attorney General Eric Holder on Thursday announced the award of a $4.75 million three-year grant to a group of educational and research organizations to study arrest data in five U.S. cities and implement changes to combat any findings of racial profiling.The cities, which have yet to be chosen, will serve as pilots to test strategies for building trust between law enforcement and the communities they serve, Holder said.Unrest in Ferguson, Missouri, following the shooting death of Michael Brown last month revived the importance of the initiative, Holder said, which originally had been announced in April.“The events in Ferguson reminded us that we cannot allow tensions, which are present in so many neighborhoods across America, to go unresolved,” Holder said.The grant will be headed by law enforcement experts from the John Jay College of Criminal Justice in New York, along with Yale Law School, the Center for Policing Equity at the University of California, Los Angeles, and the Urban Institute, a think tank based in Washington.