The CNN special "Rogue Justice" (inspired by the reporting of the N&O's Mandy Locke and Joe Neff) gave a riveting look at justice denied when the state's crime lab withheld evidence.

Tonight, there's an equally compelling companion piece to that report. "Post Mortem" (UNC-TV, 9 p.m.) investigates the dysfunction among death investigators -- coroners and forensic pathologists whose errors can condemn the innocent or let the guilty go free.