RALEIGH, N.C. — Gov. Bev Perdue on Thursday vetoed an attempt by the Republican-led legislature to weaken the state’s Racial Justice Act, which allows death row inmates to use statistics to try to convince a judge that racial bias played a role in their sentence.

It’s her first veto of 2012 and the second time she’s stopped a bill meant to undo the law.

Republicans say the law, passed in 2009, is an effective moratorium on the death penalty in the state and goes too far in allowing inmates to challenge a death sentence. The vast majority of inmates on North Carolina's death row have appealed for relief under the law, regardless of their race or that of their victims.

Proponents of the law point to a recent ruling by Judge Gregory Weeks, who agreed to commute convicted killer Marcus Robinson’s 1991 death sentence after finding by a preponderance of evidence that the state’s death penalty system is racially flawed. 

Lawmakers tried to repeal the law entirely last summer, and Perdue vetoed that move. More recently, lawmakers re-wrote the law to require that challenges include evidence beyond simple statistics to prove bias in sentencing.