Question

in cases of child custody disputes, when does detaining a child become a felony?
only if the child is taken across state lines
when the child expresses a preference to stay with the detaining parent
any time a child is detained by a parent with shared custody
when done with the intent to deprive the other parent of their custody rights based on a court order

Explanation:

Child custody-related felonies center on violating valid court-ordered custody rights with the intent to deny the other parent their legally granted access. Taking a child across state lines alone is not the sole factor, a child's preference does not legalize or criminalize the act, and detainment in shared custody is not automatically a felony. The key is intentional violation of a court custody order to deprive the other parent of their rights.

Answer:

When done with the intent to deprive the other parent of their custody rights based on a court order