A reporter discovers a man is proven innocent -- but the eyes of the law still say he's guilty

For five days, ProPublica reporter Megan Rose hunkered down in a very small, very hot conference room in Las Vegas, surrounded by boxes brimming with legal records. She took notes and scanned documents one page at a time. The grind of investigative reporting, personified. But in those pages lay a big payoff: a story of murder,…