You can file based on a "change in circumstances" since the court last addressed the issue of custody. The court will then look at the "best interest" factors in determining custody and visitation between the parents and children. You will need to prove that he is indeed emotionally harming them. This can be done by asking the court to appoint a guardian ad litem for the children and/or having the children be psychologically evaluated by a professional who will testify as to the results of such an exam.
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