A lawyer’s previous work as a Chicago assistant corporation counsel does not prevent him from representing a client suing the city after police shot her son to death, a federal judge held.In a written opinion last week, U.S. District Judge Joan B. Gottschall denied the city’s motion to disqualify Jordan E. Marsh of the Law Office of Jordan Marsh LLC.Gottschall rejected the argument that Marsh is ethically prohibited from representing the city’s adversary in a federal civil rights lawsuit because of his …