Actually, there is no DNA study worthy of the name, and the shawl has no chain of custody, AND wasn't listed as among the victim's possession. It's just a way to blame the Polack.
Nevertheless, it remains the strongest case against any of the Jack the Ripper suspects. That’s why I said that these results would never lead to a conviction but if there were to be some grand reveal of Jack the Ripper, based on this and other circumstantial evidence, I’d put my bet down on Kosminski (although I’d probably also put a small bet on none of the publicly known suspects).