In 1995, Hank Skinner was sentenced to death for a New Year's Eve triple-homicide of his family. Skinner, discovered drunk, high, and covered in blood, claims he passed out on the couch at the time of the murders, with no recollection of the events. Five years later, students from the Northwestern University start to investigate the case, and discover that key physical evidence, including the murder weapon and a jacket likely worn by the assailant, were never tested for DNA. They also discover troubling evidence pointing to a possible alternate suspect.

A 4-year-old girl from Philadelphia is found murdered, her body placed in a TV box. Police find no suspects, and the case goes cold. Years later, they arrest a neighbor, Walter Ogrod, for the crime. When an author seeking to write about the death penalty comes across Walter's case, he finds an investigation filled with holes, and a perpetrator who appears mentally unable to have confessed to the crime. The writer discovers a jailhouse snitch network and publishes a two-part article in the Philadelphia City Paper to reveal these injustices. Meanwhile, Walter Ogrod remains on death row, fighting a system determined to keep him there.