When a noncustodial parent is on the run with their child, it's a scary time for the custodial parent. While most cases are resolved without violence, there have been too many high-profile cases where the deranged parent chose to end their child's life rather than return them to their ex.
In most situations, you will want to notify law enforcement immediately upon learning that your child will not be returned to your custody. If there is no custody order in place, it can be more challenging for the police to get involved because it's assumed that both parents have equal rights to their child. "That's a civil matter," is a common response.