Does anyone know who I can contact when family member checks out of the care facility and is unreasonable mentally?

When you write "destructive", do you mean physically abusive, or that his behavior is detrimental (i.e., destructive) to her well being?

I can think of 2 options: first is to contact APS, not only for the welfare of your father but for the protection and safety of your mother. The second is guardianship, one aspect of which could be that decisions for your father's medical care are removed from him.

If a professional such as an attorney is appointed as guardian, it will be costly, but my limited experience has been through guardians appointed to provide financial and legal management of someone's affairs. I don't have that much experience with what role a guardian would play in managing someone's health care.

I would first contact APS to see what they can suggest.

Unless of course someone in the family is named as the health care proxy in an Advance Directive or Living Will for your father.

However, if your father is abusive physically, just call the police; they can remove him and have him placed somewhere to get help pending more permanent arrangements.

Good luck; this sounds like a very traumatic situation for you and your mother.

You pursue a court order to get him back in there. It's called Guardianship. Without the court ordered placement, the abuse will continue.

I can add that I recently became guardian (of the body) and conservator (of the estate) of my mother. If there is no family able or willing to perform in that role, the court will assign a service to do it and the ward's estate will pay for that work. Legally, you can get paid by the estate for your time doing the guardian/conservator work, but family tend to not take money so it can be spent on care.

Guardianship & Conservatorship are a very legitimate avenue to pursue in this situation, so you can protect dad and mom.

I can say there comes a point in our parents' lives where they just can't call the shots anymore. You have to take over for their safety whether they throw a fit or not. I've seen some spectacular ones from my mother!

If he has a dementia diagnosis, and is incompetent, the facility is in the wrong for letting him go. If something happened to him, they are liable for letting him wander. That is a very distressing turn of events. I would have me a director's head and tail on a platter for that, and their giblets carved up for the dogs.

Can you get mom away (even to your place) for a few days? It will help him feel his vulnerability to not have her there. It sounds like they are enmeshed and he will bully her as long as she's present. Tell him the doctor said your mother has to have a rest or she'll end up dead. I would be surprised if he is concerned.

And because of mom's poor health, he will have to go into care for a while until mother is better. No discussion. No debate. Let him be mad. And you & I know that mother won't be better enough to ever return to the way it was. This is where you place him in a memory care facility meant for dementia patients. He doesn't have to be told it's permanent. Once they get his meds & schedule straightened out, he might actually improve some. This is not a sign to go back home. He will not be allowed to self-discharge either.

If he goes into memory care, he will likely be seen by the visiting doctor's practice and geriatric psychiatrist. This will help him greatly.

Keep mom on respite as long as you can. Treat her somehow. Visits with dad should probably wait a while, so she can get her emotional feet back under herself and to let him cool down, get medicated properly, and settle in.

Be present at the hospital visits and make an appearance for 'discharge planning'.
Do not take him home. Please say that Mom doesn't take him home? Make some valid points, ask the hospital administrator to call a geriatric psychiatrist for a 5150 hold and examination.
You can expect that despite all your efforts, the hospital can and will call him a taxi, or he can call a friend. After a time of behaving this way, neither 911 will come nor the hospital will admit him. Then, he won't allow you to see him or mom.
So, ask your mom what she wants to do, and get her out of there.

Okay now, it is two years later, and family has done nothing for Dad or Mom. The situation has not changed. Now what? Now what? That is what you should be asking yourself. How could anyone allow this situation to continue and for Mom in her later years to have to live this way? And as for Dad, he is not a criminal, he has dementia. He needs a caregiver, right?

Mpress, it has been one week for you, your Mom, and your Dad, in a very difficult circumstance.
Is there anyway we can help you along, even if you just need to vent?
As often is the case, Dad would have come home and your family would have tried to survive under less than ideal circumstances. I have seen this happen over and over in the past two years, but thd circumstance remains ths same.

Continuing, don't feel bad if nothing has changed or if nothing can be done. Don't feel guilty, you could be proud that you were able to assess the situation more accurately and sooner, even if no one is listening. It may take them longer. Take one step at a time. Document. Be aware, are things any better today?
Your assessment is not wrong. Keep in there.