Executed by the State of California on October 19, 1928 for the kidnapping and murder of Marion Parker, a 12-year-old girl. Hickman kidnapped Parker on December 15, 1927 by appearing at her junior high school, claiming that her father, Perry Parker, was ill, and that he wanted to see his daughter. The next day Hickman sent the first of three ransom notes to the Parker home, demanding $1,500 in $20 gold certificates. On December 19, Parker delivered the ransom in Los Angeles but in return Hickman delivered the dismembered body of Marian. Her arms and legs had been severed and her internal organs removed. A towel stuffed into her body to absorb blood led police to Hickman's apartment building but he managed to escape. A $100,000 reward was offered for his capture, and for nearly a week Hickman eluded capture. He was finally caught after spending some of the ransom in Washington and Oregon. He subsequently confessed to kidnapping Marion, but blamed her murder on a man who was actually in jail during the time of the crime. Hickman was one of the earliest defendants to use California's new law that allowed pleas of not guilty by reason of insanity. However, in February 1928 a jury rejected his claim and he was sentenced to hang. He appealed the conviction and both the law and the verdict were upheld by the California Supreme Court.

Executed by the State of California on October 19, 1928 for the kidnapping and murder of Marion Parker, a 12-year-old girl. Hickman kidnapped Parker on December 15, 1927 by appearing at her junior high school, claiming that her father, Perry Parker, was ill, and that he wanted to see his daughter. The next day Hickman sent the first of three ransom notes to the Parker home, demanding $1,500 in $20 gold certificates. On December 19, Parker delivered the ransom in Los Angeles but in return Hickman delivered the dismembered body of Marian. Her arms and legs had been severed and her internal organs removed. A towel stuffed into her body to absorb blood led police to Hickman's apartment building but he managed to escape. A $100,000 reward was offered for his capture, and for nearly a week Hickman eluded capture. He was finally caught after spending some of the ransom in Washington and Oregon. He subsequently confessed to kidnapping Marion, but blamed her murder on a man who was actually in jail during the time of the crime. Hickman was one of the earliest defendants to use California's new law that allowed pleas of not guilty by reason of insanity. However, in February 1928 a jury rejected his claim and he was sentenced to hang. He appealed the conviction and both the law and the verdict were upheld by the California Supreme Court.