Unsolved murders are as compelling as anything one might see in movies; the first "crime of the century" is the mysterious murder of a Hollywood director in 1922; William Desmond Taylor is not who he seems to be, and his death continues to fascinate.

The murder of Bridget Cleary in turn-of-the-century Ireland shows the mystery of human psychology; on the surface, it seems her husband, Michael, murders her because he believes she is a "changeling" fairy in disguise; investigating this motive.

The assassination of Archduke Franz Ferdinand is one of the most world-shaking events in the 20th century; the motivation behind the murder is rife with conspiracy; diving into a cycle of mystery and violence in early 20th-century Sarajevo.

Exploring the murder of the Russian Tsar Nicholas and other Romanovs at the hands of the Bolsheviks; for more than a century, the facts of this murder are dissected and debated; time adds few facts but plenty of speculation and myth to this event.

Weimar Republic Germany is a psychologically traumatized era of madmen, sex fiends and serial killers; surveying the three Weimar-era murder cases of the sadistic Peter Kurten, the "butcher" Fritz Haarmann and the unsolved Hinterkaifeck Murders.

Delving into one of the best-known and most debated murder cases in American history; Richard Hauptmann is executed for kidnapping and killing aviator Charles Lindbergh's baby; investigating whether he acts alone and who gets the ransom money.