Intellectual Disability

Reversals Under Atkins

In 2002, the United States Supreme Court in Atkins v. Virginia declared the executions of individuals with intellectual disability unconstitutional. Since that time, states have taken divergent approaches to enforcing that constitutional right. However, some states have attempted to evade enforcing Atkins by adopting stringent definitions of intellectual disability that are scientifically unsupported or by imposing procedural requirements or burdens of proof that are impossible to satisfy.

More than 140 death-row prisoners have obtained relief under Atkins and been resentenced to life in prison. But in that same time frame, at least 28 prisoners who very likely met the prevailing clinical definition of intellectual disability have been executed and others still face execution. 

A Death Penalty Information Center analysis of data compiled by researchers and capital defense organizations on the outcomes of death-penalty intellectual disability cases confirms what researchers have long suspected, that vulnerable or disfavored classes of intellectually disabled defendants — particularly defendants of color and foreign nationals — are disproportionately subject to the death penalty. More than 80% of the death-row prisoners whose death sentences have been vacated as a result of intellectual disability (120 of 144, 83.3%) are persons of color. More than two-thirds are African American (99, or 68.8%); 16.7% (24) are white; 13.9% (20) are Latinx; and one (0.7%) is Asian. Twelve (8.3%) are foreign nationals, representing 5% of all foreign nationals known to have been sentenced to death in the U.S.

Prisoners Removed From Death Row As a Result of Intellectual Disability

According to data compiled by the Habeas Assistance and Training Project, the Cornell Center on the Death Penalty Worldwide at Cornell Law School, Justice360, and the Death Penalty Information Center as of April 15, 2021, at least 144 former death-row prisoners have obtained relief from their death sentences as a result of court decisions, plea agreements, or stipulations by prosecutors that they had intellectual disability. At least seven prisoners with intellectual disability have been removed from death row and resentenced to life in prison through the commutation process. In addition, at least six of the men exonerated from death row in the U.S. have intellectual disability.

NameStateCounty`RaceOpinion or Order Date
Jeremiah JacksonAlabamaBibbBlack9/28/06
Glenn HolladayAlabamaEtowahWhite1/30/09
Anthony LaneAlabamaJeffersonBlack9/14/18
James BordenAlabamaLawrenceWhite2/27/04
Kenneth ThomasAlabamaLimestoneWhite5/27/10
Lam LuongAlabamaMobileAsian10/15/18
Joseph Clifton SmithAlabamaMobileWhite8/17/21
Bobby TarverAlabamaMobileBlack9/24/12
Shawn GrellArizonaMaricopaWhite1/9/13
Angel MedranoArizonaPimaLatinx8/13/12
Jose RuizArizonaPimaLatinxNot recorded
Robert SmithArizonaPimaWhite2/17/16
Rudi ApeltArizonaPinalWhite5/19/09
Arturo CanezArizonaPinalLatinx9/10/07
Ramon VillarealArizonaSanta-CruzLatinxNot recorded
Rafael CamargoArkansasCrawfordLatinx8/12/04
Kingrale CollinsArkansasCrossBlackNot recorded
Sedrice SimpsonArkansasDallasBlack9/16/09
Robert YoungCaliforniaAlmaedaBlack10/8/10
George SmitheyCaliforniaCalaverasWhite8/23/10
Donald GriffinCaliforniaFresnoWhite11/12/15
Stanley DavisCaliforniaLos AngelesBlack8/31/21
Robert LewisCaliforniaLos AngelesBlack5/24/18
David FierroCaliforniaRiversideLatinx7/21/10
Noel JacksonCaliforniaRiversideBlack7/29/16
Walter CookCaliforniaSan MateoBlack11/3/14
Jose RodriguesCaliforniaSan MateoLatinx2/8/10
Calvin ColemanCaliforniaSonomaBlack8/27/08
Paul HardyFederal DPLouisiana EasternBlack11/24/10
Ronell WilsonFederal DPNew York EasternBlack3/15/16
Bruce WebsterFederal DPTexas NorthernBlack9/22/20
Charles KightFloridaDuvalWhite4/16/04
David ThomasFloridaLeeBlack2009
Sonny Boy OatsFloridaMarionBlack4/2/21
Kenneth WatsonFloridaMiami-DadeBlack1/8/07
Freddie HallFloridaSumterBlack9/8/16
Ted HerringFloridaVolusiaBlack3/31/17
Michael CohenGeorgiaGlynnBlack6/20/14
Roger CollinsGeorgiaHoustonBlackNot recorded
Johnny Lee GatesGeorgiaMuscogeeBlack2003
Gregory Rouster (Gamba Rastafari)IndianaLakeBlack6/13/03
Howard AllenIndianaMarionBlack7/3/12
Tom PruittIndianaMorganWhite6/2/15
Anthony ScottLouisianaAssumptionBlack6/26/12
Cory WilliamsLouisianaCaddoBlack2/17/06
Kevan BrumfieldLouisianaEast Baton RougeBlack12/16/15
Tyronne LindseyLouisianaJeffersonBlackNot recorded
Richard HobleyLouisianaNatchitochesBlack2004
Thomas DeboueLouisianaOrleansBlack3/10/05
Fredrick GradleyLouisianaRapidesBlack4/1/15
Jimmie MackMississippiBolivarBlack5/9/05
Kevin ScottMississippiBolivarBlack6/1/17
Lawrence BranchMississippiCarrollBlack12/2/11
William WileyMississippiDesotoBlack10/27/10
Howard GoodinMississippiLamarBlack12/13/12
Howard NealMississippiLawrenceWhite5/20/04
Mack WellsMississippiLeakeBlack6/9/05
Mack KingMississippiLowndesBlack3/26/13
William HughesMississippiTateWhite3/3/10
Steven ParkusMissouriCape GirardeauWhite4/17/07
Alis JohnsMissouriPulaskiWhite7/17/03
Andrew LyonsMissouriScottBlack1/26/10
James HillNevadaClarkBlack9/18/02
Jimmy KirkseyNevadaWashoeBlack8/21/09
Renwick GibbsNorth CarolinaBeaufortBlack6/21/04
Elton McLaughlinNorth CarolinaBladenBlack1/13/06
Billy AndersonNorth CarolinaCravenBlack12/21/10
Russell HoldenNorth CarolinaDuplinBlack10/8/04
Larry WilliamsNorth CarolinaGastonBlack7/24/06
Anthony BoneNorth CarolinaGuilfordBlack1/28/04
Dwight RobinsonNorth CarolinaGuilfordBlack11/7/03
Clinton SmithNorth CarolinaHalifaxBlack11/6/08
Jonathan LeeperNorth CarolinaMecklenburgBlack5/11/04
Robert McClainNorth CarolinaMecklenburgBlack12/11/02
Lorenza NorwoodNorth CarolinaNashBlack9/20/03
Johnnie SpruillNorth CarolinaNorthamptonBlack7/23/04
Kenneth NealNorth CarolinaRockinghamBlack3/30/15
Anthony HippsNorth CarolinaRowanBlack8/1/05
Marvin WilliamsNorth CarolinaWayneBlack2/2/12
Melanie AndersonNorth CarolinaWilkesWhite7/24/03
Abner NicholsonNorth CarolinaWilsonBlack9/20/10
Clifton WhiteOhioAshlandBlack4/9/08
Derrick EvansOhioCuyahogaBlackNot recorded
Andre JacksonOhioCuyahogaBlack8/4/22
Michael BiesOhioHamiltonWhite6/18/10
Darryl GummOhioHamiltonWhite12/8/06
Raymond SmithOhioLorainBlackNot recorded
William ThomasOhioLucasBlack1/28/10
Kevin YarboroughOhioShelbyBlackNot recorded
Paul GreerOhioSummitBlack5/17/08
Robert LambertOklahomaCreekWhite12/7/05
Darrin PickensOklahomaCreekBlack12/7/05
Roderick SmithOklahomaOklahomaBlack8/26/19
Richard HammonOklahomaOkmulgeeBlack2/26/04
Gilberto MartinezOklahomaTillmanLatinxNot recorded
Jesse PrattOregonKlamathWhite5/12/09
Michael McNeelyOregonMultnomahWhite5/12/09
Connie WilliamsPennsylvaniaAlleghenyBlack1/22/13
Jerome GibsonPennsylvaniaBucksBlack6/26/07
Joseph MillerPennsylvaniaDauphinWhite7/23/08
Jose MarreroPennsylvaniaErieLatinx1/8/09
Mark EdwardsPennsylvaniaFayetteBlack3/25/15
James VandivnerPennsylvaniaFayetteWhite2/5/18
Peter KarenbauerPennsylvaniaLawrenceWhite9/23/02
William FaulknerPennsylvaniaMontgomeryBlack7/2/02
Nathan ScottPennsylvaniaMontgomeryBlack6/30/03
Edward BraceyPennsylvaniaPhiladelphiaBlack6/16/15
Jose DeJesusPennsylvaniaPhiladelphiaLatinx1/8/18
Harrison GrahamPennsylvaniaPhiladelphiaBlack12/18/03
Simon PirelaPennsylvaniaPhiladelphiaLatinx8/20/07
Raymond WhitneyPennsylvaniaPhiladelphiaBlack1/16/08
Karl ChambersPennsylvaniaYorkWhite6/23/05
William BellSouth CarolinaAndersonBlack11/16/16
Ellis FranklinSouth CarolinaEllisBlack1/26/11
Tommy DavisSouth CarolinaGreenwoodBlackNot recorded
Edward ElmoreSouth CarolinaGreenwoodBlack2/1/10
Ricky GeorgeSouth CarolinaHorryBlack1/9/07
Kenneth SimmonsSouth CarolinaSpartanburgBlackNot recorded
Michael ColemanTennesseeShelbyBlackNot recorded
Pervis PayneTennesseeShelbyBlack11/23/21
Michael SampleTennesseeShelbyBlack2/3/2023
Willie ModdenTexasAngelinaBlack4/21/04
Pedro Solis SosaTexasAtascosaLatinx5/3/17
Timothy CockrellTexasBexarBlack6/10/09
Geronimo GuttierezTexasBexarLatinx11/25/20
James HendersonTexasBowieBlack4/15/20
Eric MooreTexasCollinBlackNot recorded
Juan LizcanoTexasDallasLatinx9/16/20
Steven ButlerTexasHarrisBlack5/25/22
Darrell CarrTexasHarrisBlack2/28/07
Gilmar GuevaraTexasHarrisLatinxNot recorded
Joseph Francois JeanTexasHarrisBlack4/19/23
Virgilio MaldonadoTexasHarrisLatinx5/22/13
Bobby MooreTexasHarrisBlack2/19/19
Daniel PlataTexasHarrisLatinx1/16/08
Demetrius SimmsTexasHarrisBlack2/28/07
Roosevelt SmithTexasHarrisBlack11/7/12
Exzavier StevensonTexasHarrisBlack3/21/07
Jose MartinezTexasHidalgoLatinx6/15/16
Walter BellTexasJeffersonBlack11/10/04
Charles BrownlowTexasKaufmanBlack1/22/21
David DeBlancTexasLibertyBlack3/16/05
Alberto ValdezTexasNuecesLatinx11/10/04
Alstyne VanTexasPotterBlack11/14/07
Clifton WilliamsTexasSmithBlack11/9/20
Juan Ramon Meza SegundoTexasTravisLatinx5/25/22

Exonerations of Death-Row Prisoners With Intellectual Disability

At least six men with intellectual disability who were wrongly convicted and sentenced to death have been exonerated in the United States since the 1970s. They include:

  • Earl Washington in Virginia;
  • Henry McCollum and Leon Brown in North Carolina;
  • Anthony Porter in Illinois;
  • Vicente Benevides in California; and
  • Rickey Newman in Arkansas.

Their demographics are similar to the individuals with intellectual disability who have obtained relief under Atkins: Washington, McCollum, Brown, and Porter are Black; Benevides is Latinx; and Newman is white. 83% are people of color — 67% African American, 17% Latinx — and 17% are white.

Washington, McCollum, and Brown all lost the legal challenges to their convictions and death sentences. Washington’s life was spared as a result of a grant of clemency. DNA later proved him innocent. McCollum and Brown were exonerated only with the intervention of the North Carolina Innocence Commission after they had exhausted their legal appeals. Porter came within two days of execution in 1998 and was spared only by a stay of execution to evaluate his mental competency. The normal legal process failed to detect his innocence: he was exonerated as a result of the efforts of an investigator and journalism students from Northwestern University.

Grants of Executive Clemency to Prisoners With Intellectual Disability

DPIC has identified at least seven prisoners with intellectual disability whose death sentences were commuted by grants of executive clemency.

  • Virginia Gov. Douglas Wilder commuted Earl Washington’s death-sentence in 1994. In October 2000, DNA tests confirmed Washington’s innocence, and he was granted an absolute pardon by Gov. Jim Gilmore.
  • Missouri Gov. Mel Carnahan commuted the death sentence of Bobbie Shaw in 1993, saying there was “little doubt” that Shaw was intellectually disabled.
  • The Nevada Pardons Board voted unanimously in 2002 to commute Thomas Nevius’ death sentence because of his intellectual disability.
  • Louisiana Gov. Mike Foster commuted Herbert Welcome’s death sentence in 2003 after the Pardon and Parole Board recommended clemency based on Atkins.
  • Texas Gov. Rick Perry commuted the death sentence of Doil Lane on March 9, 2007 after state prosecutors did not contest that Lane had intellectual disability.
  • Virginia Gov. Timothy Kaine commuted Percy Walton’s death sentence to life in prison without parole in 2008, citing serious mental illness that rendered him incompetent to be executed. Kaine said he also considered other factors such as Walton’s age at the time of the crime and evidence of “mental retardation.”
  • President Barack Obama granted clemency to federal death-row prisoner Abelardo Arboleda Ortiz on January 17, 2017. Ortiz, an intellectually disabled Colombian national, was not in the room when the victim was killed and his more culpable co-defendant received a life sentence. Ortiz’s lawyers never investigated his intellectual disability and law enforcement officials failed to provide him access to assistance from the Colombian consulate, as required under the Vienna Convention on Consular Relations.

Ways in Which States Have Evaded Enforcing the Prohibition Against Applying the Death Penalty to Prisoners With Intellectual Disability

Rather than enforcing the constitutional prohibition against executing individuals with intellectual disability, some states have adopted definitions of intellectual disability or procedural requirements that have made it impossible for some prisoners with intellectual disability to satisfy courts that they should not be executed. Some of the ways in which states have evaded enforcing Atkins include:

  • Adopting scientifically inaccurate and unconstitutionally harsh IQ test score requirements that subject some defendants and prisoners to the death penalty despite their intellectual disability.
  • Adopting scientifically baseless and unconstitutionally harsh rules for assessing the presence of adaptive deficits, including improperly substituting a consideration of adaptive skills an intellectually disabled person may have in place of examining his or her impairments in daily functioning, and basing assessments of functioning on lay stereotypes about intellectual disability.
  • Adopting insurmountable burdens of proof by requiring the defendant or prisoner to present evidence proving each element of intellectual disability beyond a reasonable doubt rather than to a reasonable degree of medical certainty.
  • Failing to make appropriate adjustments to IQ and other psychometric test scores to account for the standard error of measurement, practice effects from having been administered IQ or other tests on multiple occasions, or a phenomenon called “the Flynn effect” that shows that scores on the tests rise over time the longer the test has been in use.
  • Improperly making racial, ethnic, or socioeconomic adjustments that inflate IQ scores or discount the presence of adaptive deficits, so that a Black, Latinx, or poor defendant or prisoner would be denied a diagnosis of intellectual disability in circumstances in which a white or well-off person would have been found to have been ineligible for the death penalty.
  • Discounting adaptive deficits or qualifying IQ scores by attributing them to head injury, mental illness, personality disorder, poverty, lack of education, etc., instead of recognizing them as risk factors for intellectual disability or as comorbid conditions that may exist alongside intellectual disability.
  • Treating court decisions that have struck down use of these unconstitutional practices as “new rules of law” and refusing to the apply those decisions to correct prior decisions that assessed a prisoner’s intellectual disability claim using an unconstitutional standard.

On December 11, 2020, the federal government executed Alfred Bourgeois, whose intellectual disability claim had been denied based upon a unconstitutionally restrictive definition of the disorder. The federal appeals courts refused to hear his claim, even though the federal district court found that he had presented significant evidence of intellectual disability when the correct diagnostic criteria were applied. Corey Johnson—who medical experts say was intellectually disabled—was executed by the federal government on January 14, 2021 without ever having been provided an evidentiary hearing on his claim. Alabama death-row prisoner Willie B. Smith III was executed by Alabama on February 11, 2021 despite a determination by a federal appeals court that he met the definition of intellectual disability.

Other prisoners, such as Floyd Maestas in Utah and Thomas McCullum in Pennsylvania, who presented significant evidence supporting their claims of intellectual disability died on their states’ death rows before the courts ruled on their claims.

Executing Prisoners With Intellectual Disability

DPIC has not conducted a thorough assessment of how many individuals with intellectual disability have been executed. However, we are aware of more than 25 instances since Atkins in which states or the federal government have executed prisoners who very likely were intellectually disabled.

Executed But Likely Intellectually Disabled

RaceRace of VictimDate
Matthew ReevesALDallasBBM1/27/2022
Willie B. Smith IIIALJeffersonBWF10/21/2021
Holly WoodALPikeBBF9/9/2010
Kenneth WilliamsARLincolnBWM4/27/2017
Gary BowlesFLDuvalWWM8/22/2019
Kennneth FultsGASpaldingBWF4/12/2016
Warren HillGALeeBWM1/27/2015
Ernest JohnsonMOBooneBWF, BM, UF10/5/2021
Rodney BergetSDMinnehahaWWM10/29/2018
Carl Henry BlueTXBrazosBBF2/21/2013
Elroy ChesterTXJeffersonBWM6/12/2013
Jaime ElizaldeTXHarrisLLM (2)1/31/2006
Michael Wayne HallTXTarrantWWF2/15/2011
Yokamon HearnTXDallasBWM7/18/2012
Bobby Lee HinesTXDallasWWF10/24/2012
Robert Charles LaddTXSmithBWF1/29/2015
Milton MathisTXFort BendBWM, BM6/21/2011
Robert James NevilleTXTarrantWNAM2/8/2006
Robert Madrid SalazarTXLubbockLLF3/22/2006
Danielle SimpsonTXAndersonBWF11/18/2009
Pablo Lucio VasquezTXHidalgoLLM4/6/2016
Coy WesbrookTXHarrisWWF, LM3/9/2016
Marvin WilsonTXJeffersonBBM8/7/2012
Bobby Wayne WoodsTXLlanoWWF12/3/2009
Alfredo PrietoVAFairfaxLWF, WM10/1/2015
Kevin GreenVABrunswickBWF5/27/2008
Darick WalkerVAHenricoBBM (2)5/20/2010
Alfred BourgeoisFederalTexas, Southern DistrictBBF12/11/2020
Corey JohnsonFederalVirginia, Eastern DistrictB

BM (6)



The danger of unconstitutionally executing individuals with intellectual disability remains acute. Corey Johnson was executed by the federal government on January 14, 2021, without judicial review of his strong evidence of intellectual disability. State courts applied medically inappropriate and unconstitutionally restrictive definitions of intellectual disability to deny claims by Blain Milam, Edward Busby, Willie B. Smith III, and Ernest Johnson that they were ineligible for the death penalty. Missouri executed Johnson on October 5, 2021. Milam and Busby came within a week of execution before the Texas Court of Criminal Appeals stayed their executions (January 15 and February 3, 2021, respectively). Although a federal appeals court acknowledged that Willie Smith met the clinical criteria for intellectual disability, it refused to apply two U.S. Supreme Court decisions that demonstrated the unconstitutionality of Alabama’s rejection of Smith’s intellectual disability claim. Alabama executed Smith on October 21, 2021.

In a ruling rendered along partisan lines without benefit of oral argument, the United States Supreme Court on July 2, 2021 overturned a federal appeals court decision that had vacated the death sentence imposed on Alabama death-row prisoner Matthew Reeves, whose trial lawyers had failed to obtain expert assistance to present evidence of his intellectual disability. Reeves was executed January 27, 2022.

Pervis Payne was one of 14 Tennessee death-row prisoners with active death sentences who could not obtain judicial review of their intellectual disability claims because of defects in the state post-conviction review system. He was scheduled to be executed on December 3, 2020 but received a temporary reprieve because of coronavirus concerns on November 6, 2020. The Tennessee legislature subsequently amended the state post-conviction process to make review available and the Shelby County District Attorney’s office, which had attempted to execute him for more than two decades after Atkins was decided, conceded in November 2021 that he was ineligible for the death penalty.