My grandfather has become incredibly aggressive, borderline violent. He is suspicious and has delusions that there are prowlers and creepers in the garden and that my grandmother is conducting numerous affairs behind his back. He prowls the neighbourhood with a sharp tool he uses to kill cane toads but I'm fairly sure he’s no longer looking for cane toads, he’s looking for the “prowlers”. I need him to be diagnosed but there is no way in hell he will agree to be diagnosed.
It may be dementia or something else, like a UTI, which is very likely. It may be something like a stroke. It is very important he be evaluated. Call Adult Protective Services to tell them your concerns.
When I had a relative that lost touch with reality, the Doctor was telephoned. The advice was to call EMS for the Crises Assessment Team (as it is called here) that respond to mental health emergencies. Danger to self or to others can prompt an involuntary admission for observation & diagnosis. (It did in that case).
You may be looking at something similar.
It can be traumatic & sometimes Police need to get involved too if resistance/violence.
I would have a honest chat with your Grandmother about Grandfather's behaviour asap to judge her understanding. She may be terrified of upsetting him.. You don't want her sending EMS away, then be hurt later.
It would be helpful to know which area you/he are in, because the advice and suggestions would need to be geared to your area.
If he were in the states, I would be hesitant to call the police. Most are not equipped or skilled enough to deal with those who have mental health issues. Walking around with a "tool" used to kill cane toads and possibly being aggressive could end badly! If he's suspecting prowlers, the police could be seen as the prowlers!
Whatever location you are in, there must be social services of some kind available. Given this could become a dangerous situation quickly, they might be able to come up with a plan. It does sound like he not only needs to be diagnosed, but also receive treatment. I've often read posts from others on this site about having a LO taken in for a few days or a week, when they try to determine the cause and find the right combination of medications to tone down all the behaviors you are talking about. Getting him there is the tricky part.
Do you know his doctor? Can you call and discuss this with the doctor? Without some kind of legal authority (HIPPA here) the doctor can't discuss his condition with you, but he CAN listen to your concerns and perhaps initiate the proper plan to get the help he needs, and he NEEDS help!
If it comes down to calling the police, make it VERY clear that he has cognitive issues and you want them to send appropriate help, not just the cops.
IF there are any guns in the home, PLEASE remove them asap, when he isn't looking!
Does anybody in your family have a durable power of attorney for financial and medical? If you could add some more info that would be helpful and you will get more specific advice.
If nobody has POA then somebody will need to petition the court for guardianship. I would ask a social worker for guidance on this, and also APS. Authorities need to be alerted that your grandfather is becoming a danger, especially to your grandmother. What if he acts on his suspicions and delusions?
If nobody wants guardianship then the county may need to take guardianship. The bottom line is your grandmother needs protection, and your grandfather needs to be in a care facility.
In the end this will be most helpful to whomever has durable PoA for him. If no one has it, then guardianship is the only other pathway.