How can I sue my step mother for criminal neglect in the care of my father?

My father is in failing health. My step mother has been emotionally abusive for years. She is an alcoholic. Recently, she has refused to move with my father into a greater care wing of the residence. He agrees with what the step mother wants. They have a care giver with them in the apartment. My step mother sabotages this women, not feeding her. My step mother throws out my father's paperwork. When the aid is not there she demands that my father clean up after himself. She will not assist him with anything. She expects him to use the bathroom by himself. My father has been on oxygen. She does not monitor this. He is very weak now. He is back in the hospital and can no longer use his walker to get around. She has refused to have a new chair in the apartment which would allow my dad to more easily sit down and pick himself out of the chair. She won't allow the chair because it doesn't match the decor. This is insane. Please, I need help.