In 1902, detectives arrived at a grisly murder scene and found a shard of broken glass with several bloody fingerprints. They painstakingly searched the police station’s records and eventually found a match— a man who later confessed to the crime. Today, fingerprints remain one of the most common types of evidence in criminal courts. But just how reliable are they? Theodore Yeshion investigates. Lesson by Theodore E. Yeshion, directed by Jeff Le Bars, JetPropulsion.space.