Headless Case

One day, an elderly woman came to visit Mr. Hawthorne, crying and demanding to see him. She claimed that her daughter-in-law's head was missing and insisted that she needed to find it to prevent her son from being punished. Mr. Hawthorne, along with Longy Bao, went to the woman's residence to begin an investigation. The police suspected the husband as the murderer, but clues like footprints and earrings suggested that their conclusion was too simplistic. Who was the real murderer?