Should I accompany my father to court to force my mother into medical care?

Should I accompany my father to court to force my mother into medical care? She has undiagnosed dementia of some sort. She believes that my father has all these bank accounts that she can't know about, that he is involved in some banking scheme with "his women friends", that she signed her rights away by being tricked into signing a paper. She talks to herself constantly. She recently told me that my brother explained everything to her and now she knows why my father is doing these things. My brother never had a conversation with her. Now she is angry with me because she believes my father told me something about her and I have told everyone else. This did not happen either. I am not sure if she is dreaming or having hallucinations. She can seem so in control sometimes but other times she is so irrational. I have tried to ask her to go to a Doctor and so has my father to no avail. She is threatening sucide and she says my father tells her daily that he will kill her. She has started sleeping in another room with a chair under the doorknob. She was confiding in me and now that I have told her that she needs help and I would go with her, she has turned her anger to me. I firmly believe that she has a medical condition but I am scared to go to court with Dad and force her into getting help. My sisters and brother have chosen to not get involved. My mom is 67 and Dad is 70. He can not take much more of this and cries to me almost daily. I know that Dad is not doing any of the tings she is accusing him of and even when I prove to her that something is not true, she will just fixate on the next thing or come up with a new one. I have told my Dad that I will go to court with him but is that the right thing to do? I also have been talking with her doctor and they have tried to get her to come in to no avail as well. They finally said to call 911 when she is having one of these out of control tangents. Help - what should I do?