The murder of two grandparents tears a family apart; two decades later, a detective races to solve the cold case that has haunted him since he was a child.

Police learn the key witness in the stabbing death of a beloved aunt was an imposter; a return to the crime scene reveals a clue hidden in plain sight.

Two unsolved murders of loved ones plague a family; detectives uncover a hidden crime scene that may help solve the 13-year-old cold case.

Ten years after a young girl is kidnapped and killed on her way home from a costume party, a mistake comes to light.

A rookie cold-case detective investigating the brutal stabbing death of a bullied teenager notices a clue in an old crime scene photo that may help solve the 27-year-old case.

A killer's book about his shady past becomes the key to solving the 29-year-old cold case of two high-school sweethearts and three other unsolved murders, leading police to believe he could be the Zodiac Killer.