bruce davis ' record shows there is ` some evidence ' he is dangerous and should n't be freed , superior court judge william c. ryan wrote in a decision filed wednesday .
davis , 72 , was convicted in the 1969 slayings of musician gary hinman and stuntman donald ` shorty ' shea and sentenced to life in prison in 1972 .
he was 30 years old at the time that davis , who once bragged of cutting shea 's head off , claimed he has turned his life around in prison , earning a doctoral degree in philosophy , becoming religious and ministering to other inmates .