PONTIAC, Mich. — An attorney for the father of the Oxford High School shooter is arguing prosecutors shouldn’t be allowed to introduce evidence about his son’s mental health, his journal entries or text messages between the teen and his friend if the shooter does not testify at his dad’s upcoming trial. Since the shooter is debating whether to file an appeal of his sentence and plea, he has said through his attorneys that if he is called to testify, he will assert his Fifth Amendment right to stay silent to avoid self incrimination. Ethan Crumbley also refused to waive privilege of his medical…