(CNN) -- Forty years after they were convicted by a jury of firebombing a grocery store in Wilmington, North Carolina, civil rights activists who became known as the "Wilmington 10" were pardoned Monday by the state's outgoing governor.

"These convictions were tainted by naked racism and represent an ugly stain on North Carolina's criminal justice system that cannot be allowed to stand any longer," said Gov. Beverly Purdue. "Justice demands that this stain finally be removed."

In 1972, nine black men and one white woman were convicted in the store firebombing in the coastal city despite their claims of innocence and their supporters' vehement argument that the defendants were victims of racially biased prosecutors....