Two decades after her childhood friend, Andy Puglisi, vanished from a public pool in Lawrence, Massachusetts, documentary maker Melanie Perkins delved back into the unsolved case, looking for new clues. The intensive weeklong search that followed Puglisi’s disappearance in 1976 turned up little evidence, though most signs pointed to abduction. Perkins narrows the list of possible suspects, but a clear resolution proves maddeningly elusive. This 2006 documentary does a fine job of showing how the incident affected Puglisi’s family, friends, and working-class community, but Perkins’s presentation of her own investigation is sketchy. 79 min.