How to remove an unsafe, hallucinating mentally abusive and now threatening violence parent from your home?

Call 911 and have person removed to hospital for an evaluation

Have to agree with Vegaslady you need an assessment of the person - do whatever is necessary to get one, and if that includes 911 and a claim they are being violent and you wish to prosecute then extreme though it sounds go ahead - sometimes one has to work every system going to get necessary assistance.

And tell them you will not take them back. I doubt an AL would take on a person with these tendencies so ur only option is LTC. If parent is removed, they may be taken to a Psychic facility for evaluation and meds.