It never occurred to me before, but one of the limitations of DNA testing is that it cannot distinguish between identical twins. In the linked article a woman may have had sex with two men who were identical twin brothers on the same night, conceived a child, and is now suing just one of the brothers for child support. As DNA cannot distinguish which of the two is the father, the judge reverted to the traditional eyewitness testimony and felt that the mother was the most reliable witness and therefore took her word that the interviewed brother is the father while he is claiming otherwise.
Similarly, if identical twin brothers were accused of raping someone, or a murderer with an identical twin had left some hair at a crime scene, in neither case could the culprit be positively identified by DNA testing. It's a shame, b/c we do know that eyewitness testimony is quite unreliable.