The Grim Sleeper follows LA Weekly reporter Christine Pelisek (Walker) as she doggedly investigates the unsolved murders of dozens of women in Los Angeles and soon realizes one person is responsible for many of these deaths that began over 20 years earlier. After a string of murders in the 1980s, the violence seemed to end; but almost 14 years later, another murder spree begins, leading Pelisek to dub the killer “The Grim Sleeper.”