When William Addis was sentenced to prison in the late 18th century, he occupied himself with an unheard of task: perfecting the world's first mass-produced toothbrush.
How did one man's invention to save soldiers' lives set off an American crime wave? Which common household appliance first existed as a flattened chicken bone adorned with animal hair? And what's the connection between burglar alarms and the literary team of Holmes and Watson? We explore the origins of four inventions with criminal ties: the Tommy Gun, the home alarm, cash registers, and the toothbrush meet the brilliant minds willing to do anything to bring their innovations to the world.
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