Who is Liable if my father kills someone in an accident

My father has been diagnosed with dementia and failing eye vision, and has made dangerous decisions while driving, nearly getting in an accident on more than one occasion. None of his family will get in the car with him even though he insists on driving. We provided the neurological reports and written testimonials about his health issues and the poor driving decisions he has made, and asked that his license be taken away. Virginia gave him a written and driving test, and decided to allow him to keep his license. He has to come back for testing again in 3 years. We don't want him to drive and don't understand Virginia's decision. He should not be driving. Period.

Who is liable if he kills someone?