There is a few penal code sections that cover threats and harassment. Suggest you take your evidence (recorded or documented threats) to the police to see if a charge will stick.
Providing general answers are meant to help the poster to understand some complex legal concepts and in no way creates an attorney-client relationship.
Although the focus of your question seems to be on your wife's paramour, perhaps the better focus should be on whether your wife is violating the Parental Kidnapping Prevention Act (PKPA) by removing your child from the state and, as you indicated, hiding your child in other states. This is a question that is best addressed by consulting a family court lawyer immediately to obtain an order returning your child to this state.
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