Robert Maudsley Is an extremely violent and unpredictable man, there is a very good reason the made that cell for him.
He may have ‘only’ killed three people in prison/hospital but he attacked many more.
He openly admits he will kill again given the chance.
His cell didn’t start with nothing, but he repeatedly tried to make weapons or use items to harm himself so they had to be removed.
It is a horrible existence, but it’s the only way they have been able to keep him and others safe.