your bank should cooperate. They should have a fraud investigative unit, assuming it's an FDIC insured bank. call the po po, tell them you want to press charges, and get them to issue a subpoena to the bank asking for the utility account info connected to the fraudulent payment. get your bank to push the issue if your local PD doesn't seem proactive. also getting the bank to do this will keep you a little more in the clear should the identity thief have your address, which I am guessing is the case. it might save you a late night problem in case they come looking for you if the cops arrest them.