OSHKOSH, Wis. (AP) — A Wisconsin man who has spent two decades in prison for rape has had his conviction overturned. Fifty-three-year-old Joseph Frey has been serving a 102-year sentence for an attack on a University of Wisconsin-Oshkosh student. The woman was sexually assaulted at knifepoint after her apartment was broken into in 1991. Judge Daniel Bissett overturned Frey's conviction Wednesday after new DNA tests matched evidence from the crime scene to a man convicted of sexually assaulting two sisters, ages 12 and 13, in Fond du Lac. Those assaults happened after the attack on the UW-Oshkosh student. The man has since died. The Wisconsin State Journal reports that Frey remains in the Winnebago County Jail on $100,000 bail while prosecutors decide whether to retry him.