Police are warning Long Island parents that the person they least suspect could be a child predator.

Suffolk police say recent arrests include a Dowling college student, a Newsday returns department worker, a financial advisor and a FedEx employee. According to investigators, all four recently set up meetings online with a 13-year-old girl for sex. In all four cases, the ?girl? turned out to be a cop.

Detective Jennifer Roberts, one of the Suffolk officers who goes online posing as a kid, says recent media attention has deterred many would-be sexual predators. Officials remind parents to closely monitor what their children are doing online.