How can you trust a Dad who has attempted to place me in jail more than once?

I own the home with my mother. They have been divorced for many years. He was suppose to live with my brother but he wanted to come back after my mother was injured in an auto accident. She is diabled now and has to use a walker. I had a good relationship with my mother but with her health deteriorating, she's become angry and feels alienated. My father is ninety and is more able bodied. I work all day and have to trust him in watching over her because she is frail. She's resistant towards anyone's help. I'm overwhelmed and have done my best to cooperated with the doctors and social workers. Meanwhile, I feel like my father wants me out of the picture because he feels that I'll have him kicked out. He drinks and has been disruptive a few times. My mother insists on smoking in the home and doesn't care if I suffer from migraines. Both have been abusive for many years. I hold the bank note this to home and it's not easy for me to just move out. Sometimes I feel that they still think of me as a child. I'm fifty-six. My mother acts out violently and has struck at me. They called the police and now I have been charged with assault on an elderly person. She was the antagonist and fell. My father called the police the next day. They came to work and I was booked. It was her word against mine. She's done this before. I have some medical records of her gambling addictions and nicotine dependence but it's difficult for her to change. I have hired an attorney because even though she said she won't show for court which will have the charges dismissed but in the future, how do I prevent this from happening again.