Hello and welcome to JustAnswer. Please note: This is general information for educational purposes only and is not legal advice. No specific course of action is proposed herein, and no attorney-client relationship or privilege is formed by speaking to an expert on this site. By continuing, you confirm that you understand and agree to these terms. I am sorry to hear about this situation. 1) Technically, the checks should not have been used once the account holder passed away. Same with the credit card. There is a presumption that this was used without their knowledge and permission and this is hard to overcome. 2) To sue in a state court, one needs to have a "cause of action." There are numerous causes of action, such as "breach of contract," "negligence," "fraud," "unjust enrichment," etc., as well as causes of action rooted in statutory law. Every state has their own although they are very similar to each other in every state because they all stem from the same common law. A pleading in Court needs at least one cause of action, although it is not unusual to have more than one. Someone in your situation can try to sue for defamation. Defamation in Nevada consists of the following elements: a false and defamatory statement by defendant concerning the plaintiff; an unprivileged publication to a third person; fault, amounting to at least negligence; and actual or presumed damages. Chowdhry v. NLVH, Inc., 109 Nev. 478, 483, 851 P.2d 459 (1993)(citing Restatement (Second) of Torts, § 558 (1977)). 3. Whether or not you wish to file a suit is up to you. It may not be a good idea if there is a possibility of a criminal action against you if the heirs
are saying that they would file one. Regardless, it may be a good way to gain leverage, i.e. to threaten them to take down their statements or else face a lawsuit. I hope this helps and clarifies. Please use the SEND or REPLY button to keep chatting, or please RATE when finished. You may always ask follow ups at no charge after rating. Kindly rate my answer as one of TOP THREE FACES/STARS and then SUBMIT, as this is how experts get credit for our time. Rating my answer the bottom two faces/stars (or failing to submit the rating) does not give me credit and reflects poorly on me, even if my answer is correct. I work very hard to formulate an informative and honest answer for you; please reciprocate my good faith with a positive rating.