Serial killer H. H. Holmes built his murder castle in Chicago, but he met the hangman in Philadelphia. Al Capone served his first prison sentence here. America's first bank robbery was pulled off here in 1798. The country's first kidnapping for ransom came off without a hitch in 1874. A South Philadelphia man hatched the largest mass murder plot in US history in the 1930s. Mix in murderous maids, bumbling burglars, and unflinching local heroes and you have True Crime Philadelphia.