In United States Supreme Court in Roper v. Simmons (2005) 543 U.S. 551, the Court held the Eighth Amendment prohibited imposition of the death penalty for crimes committed when the offender was under 18. In doing so, the high court overruled its prior decision in Stanford v. Kentucky (1989) 492 U.S. 361, which had held that the Eighth Amendment did not ban the execution of juvenile offenders older than 15 years but under 18 years. (Roper, supra, 543 U.S. at p. 562.) Recognizing that "the death penalty is the most severe punishment" (id. at p. 568), the Roper court concluded "juvenile offenders cannot with reliability be classified among the worst offenders" because of three primary differences between juveniles and adults. (Id. at p. 569.) First, juveniles are less mature and responsible than adults and act more recklessly. (Ibid.) Second, juveniles are more susceptible to negative influences and pressures because they have less control over their immediate surroundings. (Ibid.) Third, a juvenile's character "is not as well formed as that of an adult." (Id. at p. 570.) The Roper court continued: "These differences render suspect any conclusion that a juvenile falls among the worst offenders. The susceptibility of juveniles to immature and irresponsible behavior means 'their irresponsible conduct is not as morally reprehensible as that of an adult.' Their own vulnerability and comparative lack of control over their immediate surroundings mean juveniles have a greater claim than adults to be forgiven for failing to escape negative influences in their whole environment. The reality that juveniles still struggle to define their identity means it is less supportable to conclude that even a heinous crime committed by a juvenile is evidence of irretrievably depraved character. From a moral standpoint it would be misguided to equate the failings of a minor with those of an adult, for a greater possibility exists that a minor's character deficiencies will be reformed." (Ibid.) The Roper court also noted that since the decision in Stanford "evidence of national consensus against the death penalty for juveniles" (Roper, supra, 543 U.S. at p. 564) had developed sufficient for the Supreme Court to conclude "that today our society views juveniles . . . as 'categorically less culpable than the average criminal.'" (Id. at p. 567.) Thirty states prohibit the death penalty for juveniles, including 12 that do not impose the death penalty. (Id. at p. 564.) Of those 30 states, five had eliminated the death penalty for juveniles either through legislation or by judicial decision after the Stanford decision. (Id. at p. 565.)