German police once took DNA samples in a jewel heist. The samples led to two twins, Hassan and Abbas O. (German law prohibits naming them in full). Both of them denied committing the crime in spite of the fact that the German police knew one of them had done it (because of the DNA evidence). Unfortunately, they could not determine which one (because their DNA is basically the same since they are twins), and German law doesn't allow suspects to be held indefinitely. For this reason the police had no choice but to let them go.
And the Vikings beat the Polynesians by another 200+ years and "discovered" America in the 1100's.