My understanding is that the police captain told Wilson that the police department as well as individual members of it had received threats, and Wilson resigned in the hopes that would pacify the people that might want to harm the Ferguson police or police department.

The response from black community leaders is that this won't make any difference because the entire police force is prejudice. Apparantly in a police force with over 50 members, only 3 are "visible minority", and that's considered unrepresentative since the city of Ferguson is mostly black.