RALEIGH, N.C. — Five death row inmates are testing a new North Carolina law that would allow them to argue racial bias played a role in their sentences, and they may soon be joined by dozens of others.

Lawyers for five prisoners filed motions in Davie, Forsyth, Martin, Randolph and Union counties Tuesday, seeking to have their death sentences converted to life in prison without parole.

The prisoners, all of who are black and had white victims, argue that racial bias, in the form of all-white or mostly white juries, helped land them on death row. Under the terms of a 2009 state law, the Racial Justice Act, the prisoners can use statistical evidence to argue their cases.

The law allows judges to consider evidence that one racial group is being punished more harshly than members of other racial groups. Only Kentucky has an equivalent law.

“We’re trying to take an objective look at it,” said Tye Hunter, executive director of the Durham-based Center for Death Penalty Litigation, which announced the filings Tuesday.

Statistical analysis of death penalty sentences allow the state to know if some convicts are likelier to face capital punishment at least partly because of race, Hunter said.

“It’s good to have some facts, and I’m confident North Carolina can figure out an appropriate way to improve,” he said.

Hunter expects there will be more motions filed before an Aug. 10 deadline set by the law, but doesn’t know how many prisoners might get involved. Of 159 convicts on death row in North Carolina, 99 are nonwhite. The 87 black inmates make up more than half the death row population, while U.S. Census estimates put the black share of the statewide population at roughly 22 percent.

District attorneys across the state are bracing for a wave of new motions filed under the law, including some filed by white death row inmates.

“We’re expecting all the people on death row to file these claims,” said Peg Dorer, director of the North Carolina Conference of District Attorneys.

“The way the law is written, it’s all about numbers, it’s not really about color,” she said. “All you’ve got to prove is that some number somewhere makes you stick out for some reason.”

Dorer said the office of state Attorney General Roy Cooper has advised North Carolina’s district attorneys to expect that all 159 inmates on death row will file motions based on the Racial Justice Act.

Messages left with Cooper’s office weren’t immediately returned Tuesday.

The motions come shortly after the findings of a study by researchers at the University of Colorado at Boulder and Boston’s Northeastern University, which concluded that a convicted killer is three times more likely to get a death sentence in North Carolina if the victim is white rather than black.

Seth Edwards, president of the district attorneys conference and top prosecutor in Martin, Washington, Tyrrell, Hyde and Beaufort counties, has said race doesn’t play a factor in prosecutors’ decisions to seek the death penalty.

The five prisoners who filed motions Tuesday are Kenneth Rouse, who was convicted in Randolph County in 1992; Guy LeGrande, convicted in Stanly County in 1996; Shawn Bonnett, convicted in Martin County in 1996; Jeremy Murrell, convicted in Forsyth County in 2006; and Jathiyah Al-Bayyinah, convicted in Davie County in 1999 and again in 2003.