Today is the start of the federal death penalty trial of Dylann S. Roof, the white man accused of murdering black worshipers at the Mother Emanuel church in Charleston, S.C. The killings of “the Charleston Nine” last year were as violent and seared with racial hatred as the 1955 lynching of Emmett Till in Mississippi and the 1963 bombing of an Alabama church that killed four little girls.


Although this crime was meant to challenge the black community’s right to exist, the NAACP Legal Defense and Educational Fund opposes the death penalty for Mr. Roof. Such a sentence would have the perverse effect of justifying the routine, racially discriminatory imposition of the death penalty on black people.


The Legal Defense Fund, which, despite its name, has been a wholly separate entity from the N.A.A.C.P. since 1957, has a long and storied history of opposition to capital punishment. Our founder, Thurgood Marshall, defended numerous black men facing death sentences and executions in the South, including the Groveland Boys in 1951, who were falsely accused of raping a white woman in Florida and condemned to death.


We also challenged the constitutionality of Georgia’s death penalty in the case of Warren McCleskey, a black man convicted of killing a white police officer, by presenting evidence showing that black people convicted of killing white people were more likely to be sentenced to death than those convicted in cases involving any other racial combination of defendant and victim. The Supreme Court’s 1987 decision upholding Mr. McCleskey’s death sentence notwithstanding this powerful evidence of systemic racial bias remains one of the most controversial decisions of our time.


Last month, my colleagues and I argued Duane Buck’s case in the Supreme Court. Mr. Buck was condemned to death in Texas after his own trial lawyers presented an expert opinion that he was more likely to commit criminal acts of violence in the future because he is black.


At the time of his 1997 trial, the district attorney’s office in Harris County, which includes Houston, was more than three times as likely to seek the death penalty for black defendants like Mr. Buck, and Harris County juries were more than twice as likely to impose death sentences on black defendants than on comparable white defendants.

Florida, Georgia and Texas are hardly anomalous — studies repeatedly show that race plays a pernicious role in the administration of the death penalty across the country, from Pennsylvania to Washington. The Legal Defense Fund has long recognized that capital punishment is a deeply flawed institution that consistently, and unfairly, threatens and takes black lives. As a result, we are institutionally opposed to the death penalty in all cases.


But some will surely say Mr. Roof’s case is a far cry from the Groveland, McCleskey or Buck cases because Mr. Roof is a young white man charged with murdering nine black people while they prayed in church. As a result, this crime brings into sharp focus our country’s fierce debates over race, criminal justice and capital punishment. Justice must be done, and our nation must recognize and condemn these killings as an attack on the very fabric of our society.


But the reality is that the death penalty has not only failed to serve the black community well, it has failed to serve any community well. Mistakes are common: A comprehensive study of death sentences imposed between 1973 and 1995 found reversible errors in nearly 70 percent of cases, and some 156 people who were condemned to death have now been exonerated.


Furthermore, a small group of prosecutors have had an outsize influence over the administration of the death penalty in this country: A mere five of the country’s 2,400 chief prosecutors are responsible for the sentences of one out of every seven prisoners on death row. For these and other reasons, a recent study from the Pew Research Center found that Americans’ support for the death penalty is at its lowest level in more than four decades.


Justice Anthony Kennedy warned in a 2008 decision reiterating the unconstitutionality of the death penalty for non-homicide offenses that “when the law punishes by death, it risks its own sudden descent into brutality, transgressing the constitutional commitment to decency and restraint.” As is true for Mr. Roof. His case, in all its stark egregiousness, is the exception that proves the rule: Supporting the death penalty for Mr. Roof means supporting the use of a punishment that will continue to be inflicted on people who are nothing like him.


In opposing the death penalty for Mr. Roof, the Legal Defense Fund does not speak for the survivors or the families of the victims; we grieve with and for the Mother Emanuel and Charleston communities. We recognize that there is a broad spectrum of emotions and positions on this volatile issue, and that the voices for justice that have emerged in the wake of these murders stand on their own and deserve our compassion and respect. We at the Legal Defense Fund can speak only for ourselves, based on our organization’s 75 years of experience with grieving families and communities, with victims and defendants and our quest for racial justice.


We believe that justice can and should be served without a death sentence for Dylann Roof. Our communities and our country will be better off without executing him.

Christina Swarns is the director of litigation at the NAACP Legal Defense and Educational Fund.