Everywhere has its myth to scare kids away from the bad places. Along the border, it's La Llorona near water. In England, it's the boggart on the moors. On Staten Island, it's Cropsey at the abandoned asylum. But this unnerving documentary asks: What if Cropsey is real?

The starting point here is the trial of Andre Rand, charged with the 1987 abduction and murder of 12-year-old Jennifer Schweiger on the sleepy island. But just as the community started to connect him to more missing children, and this puny outsider filled the mythical role of Cropsey for the local kids, film makers Barbara Brancaccio and Joshua Zeman aim broader. Their Staten Island isn't a leafy suburb off Manhattan, but a polluted dumping ground and a secret burial ground for mob corpses.

Last time a documentary blurred the line this much between verite and horror was probably Wisconsin Death Trip, but there's no cozy chintz of history to soften the sins. Much is traced back to the horrific and abandoned Willowbrook Mental Institution, where the first body is found and where innocence was violated long before Rand came on the scene.

The question here is about the line between real story and urban legend. In this age of meta this and post that, it's easy to forget that fairy tales often weren't metaphor or allegory for anything, just warnings about getting eaten by wolves or taken by strangers. But Brancaccio and Zeman suggest that, whetever Rand's crimes, Staten Island has turned him into their bogeyman. Were Cropsey and Rand really the same thing? Or, possibly even scarier, did Staten Island try to paint Rand as Cropsey, a psychological dumping ground for all their guilt and sins and fears, just as they have been New York's repository of dirty little secrets?

Nothing is answered definitively here. But if there's a real Cropsey to be found, it may be Staten Island itself. As one guard is bleakly quoted as saying, if Rand was innocent after all, he's become a martyr for the safety of children.

Cropsey is available now on DVD from the filmmakers.