they need the killer to not get away with it, so they created a scapegoat. they picked an affluent white guy because the system is more lenient on them. they approach him, offer him and his family money, tell him he'll have to spend a few years in jail, take the fall for the murder, and promise that he'll be out soon, private cell, lenient judge, all that. that way the public thinks that it's not possible to get away with revolt.