CINCINNATI — DNA tests disproved a teenager's claim that he was an Illinois boy who disappeared eight years ago, the FBI said Thursday, dashing hopes that the baffling case had finally been solved.For a day and a half, a breakthrough seemed to be at hand when a teenager found wandering the streets of Newport, Kentucky, on Wednesday identified himself as 14-year-old Timmothy Pitzen and claimed he had just escaped from two men in the Cincinnati area who had held him captive for [...]