Nearly every adult who wants to work with children in the U.S. — from nannies to teachers — has undergone state screenings to ensure they have no proven history of abusing or neglecting kids. But The Associated Press has learned that a major exception is the staff at two federal facilities holding 3,600 migrant teens in the government's care.

Florida law bans any outside employer from reviewing information in its child welfare system, so the child abuse background checks aren't being conducted at a Miami-area detention center. The federal facility does ensure its staffers pass criminal history and FBI fingerprint checks, however.

A tent city in Tornillo, Texas, also is not putting staff through the child abuse background checks routinely required for adults who work with children.