At the end of the nineteenth century, Canada’s prairies were still sparsely populated. Crimes such as horse theft, random murders, and prison escapes were the order of the day, and the North West Mounted Police continued to rely on their horses, their contacts, and their wits to apprehend the culprits. By the mid-1930s, a sea change in technology and police science had changed the game. Major advances in transportation, communications, and sleuthing techniques made crime-solving a new art—but the criminals also had access to the new ways.The US had Bonnie and Clyde, and John Dillinger, but Canada had its fair share of bad apples committing equally vicious crimes: a serial rapist and strangler who most often chose female proprietors of rooming houses as his victims; a father-and-son murder team, tracked by an enterprising detective all the way to Kentucky; and a group of murderous youths who sparked a manhunt across two provinces and a bloody shootout resulting in the deaths of four policemen. These stories offer an intriguing look at the skill, determination, and bravery of Prairie law enforcers as they risked their all to bring ruthless outlaws to justice.