It might be more merciful to drop a Mk-41 25mt and let the pieces fall where they will.
Seems to me, the city of Detroit hired only those that were willing to be the most corrupt bureaucrats looking for the "it's my turn to get a piece of the pie" upstanding residents.
In a world full of corruption it's sad to say the only solution would be to have them all swept out of their corrupt positions voluntarily but since none would submit to this and you obviously refused to then dispatch them with extreme prejudice. Blood sucking vampires they all are and the host is dead but nobody wants to kill the parasite. DemonRats, hate'm.