DPI’s Podcast 12:01 The Death Penalty in Context: Experts Discuss the Legacy of Roper v. Simmons

In this month’s pod­cast episode of 12:01: The Death Penalty in Context, DPI’s Managing Director Anne Holsinger speaks with Professors Craig Haney and Frank Baumgartner, and DPI’s Staff Attorney Leah Roemer about the lega­cy of the US Supreme Court’s deci­sion in Roper v. Simmons and the legal and sci­en­tif­ic land­scape sur­round­ing the use of the death penal­ty for young adults ages 18 – 20. Professors Baumgartner and Haney, along with fel­low researcher Karen Steele, col­lab­o­rat­ed on a 2023 study which dis­cuss­es the legal con­text and ratio­nale of the Court’s deci­sion in Roper when it barred the death penal­ty for juve­niles under age 18. Ms. Roemer is a major con­trib­u­tor to DPI’s new report, Immature Minds in a ​“Maturing Society”: Roper v. Simmons at 20.

Professor Haney explains how neu­ropsy­cho­log­i­cal research influ­enced the Roper deci­sion by show­ing that juve­niles are less respon­si­ble, more impul­sive, more eas­i­ly influ­enced by exter­nal fac­tors, and have less fixed per­son­al­i­ties, mak­ing them more amenable to reha­bil­i­ta­tion. However, recent sci­ence shows these same brain devel­op­ment pat­terns con­tin­ue well into a person’s twen­ties. ​“18‑, 19‑, and 20-year-olds, it turns out, from a neu­ro­bi­o­log­i­cal and neu­rode­vel­op­men­tal per­spec­tive, are still very much in the process of mat­u­ra­tion, indis­tin­guish­able essen­tial­ly from 16‑, 17‑, and 18-year-olds,” says Professor Haney. This con­tin­u­ing brain devel­op­ment led the American Psychological Association to rec­om­mend extend­ing the Roper exclu­sion to these young adults.

Ms. Roemer shares find­ings from DPI’s research on sen­tenc­ing trends since Roper: ​“In the five years after Roper, there were 92 total death sen­tences for peo­ple under 21…But in the past five years, since 2020, there have only been five death sen­tences for this age group total.” This sig­nif­i­cant decline means only about one per­son between 18 – 21 is sen­tenced to death each year, with the prac­tice iso­lat­ed to just four coun­ties in three states over the last five years. Approximately 30% of young adults sen­tenced to death after Roper have already been removed from death row through over­turned sen­tences or commutations.

Professors Haney and Baumgartner dis­cov­ered pro­found racial dis­par­i­ties in death sen­tenc­ing for this age group. ​“Among those in the late ado­les­cent class aged 18 to 20, only 20% are white. 80% are peo­ple of col­or,” Professor Baumgartner reveals in dis­cussing death sen­tences hand­ed down to young adults between 1972 and 2021. DPI’s research iden­ti­fied sev­en states where every sin­gle young adult ages 18 – 20 sen­tenced to death since Roper was a per­son of col­or, and three juris­dic­tions where every per­son exe­cut­ed in this age group was a per­son of col­or. In Texas, 94% of peo­ple cur­rent­ly on death row for crimes com­mit­ted under age 21 are peo­ple of col­or. Professor Haney attrib­ut­es this dis­par­i­ty part­ly to the ​“adul­ti­fi­ca­tion” of young peo­ple of col­or, where they are per­ceived as old­er and more respon­si­ble than white peers of the same age, caus­ing jurors to view their youth as less of a mitigating factor.

The pan­el dis­cuss­es Marion Bowman, who was exe­cut­ed in January 2025 in South Carolina for a crime he com­mit­ted at age 20, as an exam­ple of how racial bias affects per­cep­tion of youth. Despite being just 20 at the time of his crime, his tri­al attor­ney referred to him as a ​“man” while call­ing the 21-year-old white vic­tim a ​“lit­tle white girl.” Mr. Bowman had devel­oped into what the chief psy­chi­a­trist over­see­ing the state’s death row called ​“pos­si­bly the most respect­ed per­son on death row” with ​“a near­ly spot­less prison record,” yet was still executed.