Retiring Justice Sandra Day O'Connor's evolving skepticism about capital punishment has played a significant role in a number of key decisions regarding the death penalty throughout her 24 years on the U.S. Supreme Court. During public appearances in recent years, she has often mentioned her concerns about innocence and the need to protect a capital defendant's constitutional right to adequate representation. In a 2001 speech she stated, "Serious questions are being raised about whether the death penalty is being fairly administered in this country. If statistics are any indication, the system may well be allowing some innocent defendants to be executed."
From the bench, O'Connor was a key vote in the 2002 ruling to ban the execution of those with mental retardation and she has been among the U.S. Supreme Court Justices who have criticized Texas courts and the U.S. Court of Appeals for the 5th Circuit. In 2004, she questioned the Texas Court of Criminal Appeals for upholding a death sentence despite a ruling by the U.S. Supreme Court that the instructions given to jurors had been constitutionally flawed. In that case, she wrote that the ruling "has no foundation in the decisions of this court" and said the judges had relied on "precisely the same 'screening test' we held constitutionally inadequate" in a previous decision.
Capital defense attorney George Kendall, who has worked on many cases before the U.S. Supreme Court during O'Connor's tenure, noted, "As time went on, she became less enamored with the death penalty. She took a case-by-case approach. Her instincts were largely quite conservative, but like many people in the past 5 or 6 years, she began to have questions and to see that there are a lot of problems with the administration of the death penalty." (Houston Chronicle, July 4, 2005). See Supreme Court, New Voice, Innocence, and Representation.