Buffalo attorney Barry Covert uses a dry-erase board in his office at Lipsitz Green Scime Cambria to jot things down and piece together complicated aspects of cases for clients and colleagues. As he laid out the scene from the recent decisions of grand juries in Ferguson, Mo., and Staten Island that cleared police officers in the deaths of unarmed men, he had a hard time making sense of what he says are the "disappointing" processes involved. Prosecutors typically present the case and then ask…