I believe the woman they are re-interviewing is not the Oct 22nd vic, but the other one from Oct that was announced yesterday. From the below link:
http://www.ktvn.com/Global/story.asp?S=7908514
Just Wednesday, university police alerted students about a newly reported groping that took place near campus in October. But Reno police say the woman in that case had already came forward. "We have interviewed her, her comments to us at the time lead us to believe it wasn't connected. That it was possibly a prank," says Lt. Bob McDonald.
Reno police re-interviewed that woman Thursday afternoon about why she reported it again as something more serious.
ETA: I don't think the woman thought it was a prank originally, otherwise she would not have reported it. And LE wonders why she is coming forward again? Maybe she is because they treated it like it was a prank and didn't take her seriously the first time!!!