Help!

Does anyone know if a father can get full custody from a child when there's evidence that the mother is an unfit mother? Meaning the child says that his mom wants to kill his daddy and grandma. Also that his mom is teaching him bad words and is teaching him to be a gangster. The child is 5 years old. I video taped him and let him know I was recording. Do we need a lawyer to show the videos or the judge won't care?