kellir, you can add details and a legal question to your first post by using the "edit post" feature, or you can "reply to thread" and add information that way. The preview post function on this site does not work for all people all of the time and can delete content upon submission. I imagine that is what happened both to the content in this thread and to the content in your "warrant" thread.
How did you learn of the theft from your mailbox? Do you know the person who stole and cashed your check? Did you report this theft to the police (and to the USPS)?