Miyako Hiraoka, a freshman at the University of Shimane, was a good student without absence. She had been missing since Oct. 26, when she failed to return to her dormitory after finishing her part-time job.

A joint police squad has determined through an autopsy that Hiraoka was killed within five days of her disappearance, investigative sources said. Her head, discovered by a mushroom hunter on the slope, showed signs Hiraoka was struck in the face. Police are trying to determine Hiraoka's last known whereabouts after she left work and are in contact with her friends and colleagues.