Co-anchor Deborah Roberts investigates the murder of Rusty Sneiderman in an all-new, gripping episode of “20/20,” Friday ... investigation led to the mystery gunman, Hemy Neuman.

Now, ABC News is airing a one-hour documentary special about the murder, Mangione, and the nation's response. Titled "Manhunt: Luigi Mangione and the CEO Murder - A Special Edition of 20/20," the ...