Answer:
Bryan Hartnell, one of the Lake Berryessa victims, described the man that attacked him and his girlfriend Cecelia Shepard on September 27, 1969 as dressed all in black. He wore a black hood with eyeholes and the trademark 'gun site' symbol on his chest. Black boots and a belt that held a gun and knife, completed the ensemble.
At other times he was described as wearing dark pants, dark blue jacket and black boots.