Seventy years ago this week, Dragnet made its radio debut and changed the face of crime drama forever. That first episode launched a franchise that stretched into the 21st century and made its creator and star Jack Webb a household name. We'll celebrate the anniversary with four cases pulled from the files of the LAPD: "Homicide" (originally aired on NBC on June 10, 1949); "The Big Fake" (originally aired on NBC on June 1, 1950); "The Big Bible" (AFRS rebroadcast from 9/28/1954); and "The Big No Tooth" (AFRS rebroadcast from 4/5/1955).