Philadelphia District Attorney Larry Krasner, who campaigned in 2017 as an unequivocal opponent of the death penalty, asked the Pennsylvania Supreme Court in a legal filing Monday night to declare the state’s death penalty system unconstitutional.

The death penalty as it stands “cannot survive the state Constitution’s ban on cruel punishments,” Krasner wrote in a brief he submitted to the state’s high court. He cited a study, conducted by his office, that revealed a startling 72 percent of Philadelphia death sentences were overturned during post-conviction review between 1978 and 2017, often due to ineffective legal representation. In a justice system rife with racial disparities, that 37 of the 45 people from Philadelphia currently on death row are black adds even more cause for concern, Krasner argued.

While grassroots opposition to the death penalty has grown with increasing evidence of wrongful convictions, it is rare for prosecutors themselves to call for its end. Krasner joins a small group of prosecutors who have called for their states to end the death penalty — where it still exists — including Boulder County District Attorney Michael Dougherty in Colorado, King County Prosecuting Attorney Dan Satterberg in Washington, and former Washoe County homicide prosecutor Thomas Viloria of Nevada.

Krasner’s declared opposition to his state’s death penalty comes after a week during which his office was embroiled in a high-profile controversy with Attorney General Josh Shapiro, whose office was recently granted authority by the legislature to prosecute some gun crimes in Philadelphia — a move that was viewed as an attempt to undermine Krasner’s prosecutorial reforms. Shapiro says he did not ask to have jurisdiction over gun crimes in Philadelphia County alone. On Friday, under pressure from activists, he said he would support a repeal of the new law.

The reformist district attorney’s filing once again pits him against Shapiro’s office, which defends state laws that face legal challenges. Last summer, the attorney general opposed a request by the Philadelphia federal defender’s office that the state Supreme Court declare the death penalty unconstitutional. Shapiro argued that, if the Supreme Court agreed to do so, it would be overstepping its authority by setting policy from the bench.

The federal defender’s request came in the case of an appeal from Jermont Cox, who is on death row following a 1993 conviction for first-degree murder and a series of other charges stemming from three 1992 shootings, and Kevin Marinelli, who has been on death row since he was convicted in 1995 for the murder of Conrad Dumchock. As a result of their appeals, the Supreme Court agreed to consider whether the state’s death penalty system is so flawed that it violates the Constitution. Krasner’s filing opposing the death penalty came as part of that case. Shapiro, in a separate Monday night filing to the Pennsylvania Supreme Court, argued that review of Marinelli’s case should be denied and deferred to the legislative branch.

A number of outside groups, including the American Civil Liberties Union, have submitted briefs in this case arguing that Pennsylvania Supreme Court should find that the death penalty as currently applied violates the state Constitution. In an amicus brief filed on behalf of Cox and Marinelli, the American Civil Liberties Union, which opposes capital punishment, argued that the death penalty has been imposed upon “those who have received the worst representation,” not those who are the most “deserving of execution.”