Rob Taylor / AP North Carolina Gov. Pat McCrory speaks during a National Day of Prayer observance at the Pitt County courthouse in Greenville, NC.

WINSTON-SALEM, North Carolina — North Carolina's governor, hoping to resume executions in his state, on Wednesday signed the repeal of a law that has allowed death row inmates to seek a reduced sentence if they could prove racial bias affected their punishment

The Racial Justice Act, the only law of its kind in the United States, had led to four inmates getting their sentences changed to life in prison without parole after taking effect in 2009.

Supporters said the historic measure addressed the state's long record of racial injustice in its capital punishment system, while critics said it caused unnecessary costs and delays after nearly all death-row inmates, including whites, sought relief under the act.

Governor Pat McCrory, a Republican, said repealing the law would remove the "procedural roadblocks" that had kept North Carolina from executing anyone since 2006 despite there being 152 people on death row.

"The state's district attorneys are nearly unanimous in their bipartisan conclusion that the Racial Justice Act created a judicial loophole to avoid the death penalty and not a path to justice," McCrory said.

Republican lawmakers gutted the Racial Justice Act, passed when Democrats controlled the legislature and governor's office, after winning the majority in the state's General Assembly.

The American Civil Liberties Union of North Carolina criticized the repeal on Wednesday and accused state leaders of ignoring widespread evidence of systemic racial bias.

Statistics show that of the 152 people on death row in North Carolina, 80 are black, 62 are white and the remainder fall into other racial categories in a state where African Americans overall make up around a fifth of the population.

The repeal applies retroactively to cases with pending Racial Justice Act claims, a factor certain to result in additional legal wrangling, one death penalty expert said.

"To me, it's a violation of due process," said Mark Rabil, director of Wake Forest University law school's Innocence and Justice Clinic in Winston-Salem. "I don't really know what the legislature thinks they've done with our money other than buy a lot more litigation."