The Golden State Killer invaded homes, tortured and terrorized families, committed fifty brutal rapes and thirteen vicious murders, and was on the loose for forty-four years. Cold case Investigators chased down thousands of leads without ever getting their man. But a new forensic tool breaks the case and exposes this remorseless predator – Joseph DeAngelo – his family, his background, and his life story; and finally, scores of victims get a measure of long-awaited justice.