In the early morning hours of February 7, 1992, a 79-year-old woman was brutally murdered in the Charlotte, North Carolina, apartment where she’d lived for two decades. Viola Pendergrass — who neighbors called “ma” and was revered as the matriarch of her own sprawling family — was found stabbed to death in her bedroom. Her murder divided a once close-knit family and has stumped police for 30 years.