At the age of 15, William Thompson brutally murdered his brother-in-law, who had been abusing his sister. According to Oklahoma law, Thompson was a minor and must be tried as one, thereby receiving a reduced sentence and other considerations. Due to the gravity of the crime, the prosecutor requested an order which would allow the boy to be tried as an adult. In order to do this, the prosecution had to demonstrate that the case had merit and that the chance for rehabilitation of the child within the juvenile system was slim. An Oklahoma District court granted the order after hearing of the boy's violent nature, past offenses, and psychiatric testimony. Thompson was convicted of first-degree murder and sentenced to death. The ruling was appealed and the Supreme Court overturned the death sentence, holding that "[t]he Eighth and Fourteenth Amendments prohibit the execution of a person who was under 16 years of age at the time of his or her offense." The Court thereby ruled that applying the death penalty to a 15 year old was prohibited under the Constitution's cruel and unusual punishment clause.