What is your plan? What are you going to do if you catch the thief? Law enforcement is best left to professionals. Of course, the bank has information that they are not sharing with you. You do not have a right to it. They will share that information with the police and the police will know how to find the thief (if anyone can), how to charge him/her with the appropriate crimes, and how to prepare a report for the District Attorney so that the prosecution can be properly handled. This is not a place for amateurs. I urge you to involve the police and let them do their job.
It seems as if you are doing detective work more suited to a police investigation. If you have not already made a formal complaint to law enforcement, you should do so as soon as possible.
I would also recommend retaining a local attorney to assist you in this endeavor.
I am not your attorney, I do not represent you. This response is submitted for informational purposes only. This is not legal advice, nor is it intended to be taken as such. Anyone considering the above referenced situation should always consult an attorney within the jurisdiction before taking any action based on this, or any other information.
A person whose property has been stolen should make a police report. Law enforcement will be better able to investigate a check theft/check fraud crime.
Additionally, because most businesses require some identification to cash a check, the person who cashed the check may have used the victim's identity. This suggests the person may have some of the personally identifying information about the victim beyond just the name. The victim would thus be wise to take steps to protect himself or herself against possible further identity theft. The Federal Trade Commission (FTC) provides and excellent guide to the steps the victim should take to safeguard the credit report. You can read the FTC guide at this link: http://www.ftc.gov/bcp/edu/microsites/idtheft/consumers/defend.html.
(The attorney responding is licensed only in the state of North Carolina. This response does NOT constitute legal advice and does NOT create an attorney/ client relationship! Rather, the response is in the form of legal education and is intended to provide general information about the matter in question. Although a response is provided to the specific question, there may be other facts and law relevant to the issue that the questioner has left out and which would make the reply unsuitable. Therefore, the questioner should not base any decision on the answer, but should confer with an attorney in person about the specifics of his or her case.)