Joshua Swalls, 22, vanished without a trace from a friend's apartment in Indianapolis where he was staying this month. He was last seen in the early morning hours of November 4th, 2012. Police say they recently found a shoe in the vicinity of the residential complex which they believe may belong to the missing young man. Divers then fruitlessly searched for Swalls' body in the nearby retention pond for approximately an hour.
How did they know to do that?