In October, immigration authorities released Vanian — a convicted felon who served a sentence for carrying a loaded firearm — because they could not get a valid passport to deport him.
snip....Immigration authorities are bound by a U.S. Supreme Court decision that prohibits keeping detainees for more than six months beyond their prison sentences if deportation is unlikely. In some cases, the government finds a third country to accept the immigrants, but more end up back on U.S. streets.