On September 9, 1993, Christopher Simmons and a friend bound Shirley Cook in duct tape and electrical cables, beat her, and threw her into a river from a bridge. The coroner for St. Louis County, Missouri, ruled her death a drowning.

The evidence against Mr. Simmons was overwhelming. He had clearly premeditated the attack and murder, had bragged about it later, and he confessed to the police. He went so far as to re-enact the attack and murder for the police. There was witness testimony against him as well. The jury had no option but to find him guilty beyond a reasonable doubt.

Mr. Simmons was then sentenced to death for first degree murder. In the sentencing phase of his court case, his defense attorneys failed to bring out extensive mitigating evidence of Mr. Simmons' horrific childhood history of abuse and drug and alcohol abuse. For example, his stepfather would beat him regularly, neglect him as a toddler, and feed him alcohol at ages as young as four in order to entertain the father's friends.

On appeal, Mr. Simmons argued he had ineffective counsel because this mitigating evidence was not brought to light. In fact, at least one juror who sentenced him to death could not understand why a person who was presented as being an upstanding citizen could snap and engage in such horrible behavior.

The trial court hearing the appeal did not agree with Mr. Simmons' argument, so it was sent to an Appeals Court. This is where the case gets really interesting.

Even though he was an adult at the time of his conviction and sentencing, Mr. Simmons was only 17 at the time of the murder. His new attorneys dropped the issue of ineffective assistance of counsel and focused on his age and his potential diagnosis of mental retardation. They argued the case all the way to the Missouri Supreme Court, which held that it would be considered cruel and unusual punishment (Eighth Amendment) to execute an individual who was mentally retarded. It would also be a violation of the Eighth Amendment to execute a juvenile under the age of 18 at the time of the offense.

The State of Missouri appealed this decision to the U.S. Supreme Court, who agreed to hear the case in 2004.

Missouri argued that executing a 17 year-old is not an Eighth Amendment violation, due to the Court's decision in 1989 upholding death sentences for juveniles ages 16 or above (Stanford v. Kentucky). Complicating the state's case, however, was Atkins v. Virginia (2002), where the Court found executing someone who is mentally retarded to be unconstitutional.

After hearing oral arguments, the Court deliberated and issued a ruling in 2005. They upheld the Missouri Supreme Court's decision to set aside Mr. Simmons' death sentence. They cited statistics in their ruling indicating a majority of states had already outlawed death sentences for juveniles, and they noted Americans view juveniles as "categorically less culpable than the average criminal." The scientific basis for this ruling was explained as follows:

"(1) the lack of maturity and an underdeveloped sense of responsibility were found in youth more often than adults and were more understandable among the young;

"(2) juveniles were more vulnerable or susceptible to negative influences and outside pressures, including peer pressure; and

"(3) the character of a juvenile was not as well formed as that of an adult."

As a result of this case, Mr. Simmons' sentence was reduced from death to life in prison without parole. And, the U.S. Supreme Court created a new standard for the death penalty--it is now a violation of the Eighth Amendment to execute anyone who committed murder prior to the age of 18, regardless of how old the person is at the time of trial and sentencing.