"Earlier studies have shown that arrests depend heavily on witnesses' or victims' identifying or carefully describing the suspect (Greenwood, Petersilia, Chaiken, 1978). Prosecutors may have a more difficult time making cases against minorities "beyond a reasonable doubt" because of problems with victim and witness identifications. Frequently, witnesses or victims who were supportive at the arrest stage become less cooperative as the' case proceeds. Defenders of the system argue that the statistics do not lie, and that the system does not discriminate but simply reacts to the prevalence of crime in the black community."