Hundreds of immigrants convicted of sex crimes should have been deported but instead were released in the U.S. because their homelands refused to take them back, reports the Boston Globe. They are convicted rapists, child molesters, and kidnappers, among “the worst of the worst,” as one law enforcement agency put it. Immigration officials released them without making sure they register with local authorities as sex offenders. Once U.S. Immigration and Customs Enforcement (ICE) frees them, agency officials often lose track of them, despite outstanding deportation orders. By law, police are supposed to investigate if sex offenders fail to update their address within days of their release. Local officials said they did not learn that ICE had released the offenders until after the Globe inquired about their cases.