How did they catch criminals in medieval Europe?

Medieval, "police," typically called upon all citizens of a community to catch and deliver a criminal. Citizens who didn't participate were often fined, although being the criminal was much worse. Citizens who suspected foul play would raise a, "hue and cry," in which the local authorities would respond to. Medieval communities were often responsible for their own protection, so they tended to lean more towards heavy punishments rather than wasting time catching criminals. Thieves who were found guilty were hanged...enough said.