My question involves defamation in the state of: CA (sender location unknown)
My widowed / single mom sister received a vicious anonymous letter accusing her of being mentally ill, committing insurance fraud and abusing her child with special needs. It also stated that her other child was sexually assaulted by a man who was previously accused of assaulting her child with special needs but that my sister had "hidden" this information from the cops to "protect" the child's "reputation". The assault case involving her child with special needs was dismissed & the individual had never had any contact with her other child. Both children are minors. My sister lives in California and has no idea who could have written this to her.
Coincidentally, CPS contacted her a few days after she received the vitriolic letter. It is her suspicion that this letter writer may have also reported her to CPS. Since the allegations are patently false, is there a way she could find out who the sender is? Will USPS even help her? CPS investigated, said they will close the case as unfounded but she has not heard from them after that (maybe due to the lockdown / shut down)? Is there anyway the police would help her or is this purely a "civil matter"? How can she find out who this individual is? Does she have a defamation case against this anonymous person?,