BROOKINGS, S.D. (MITCHELLNOW)Police in Brookings are warning residents and businesses to watch for counterfeit $50 bills circulating in the area. The Brookings County Sheriff’s Office says the fake bills all share the same serial number, have a lighter blue tint near President Grant, and feel different from real currency. The department recommends using counterfeit detector pens to verify cash. Similar counterfeit $50s were also reported earlier this month in Big Stone County, Minnesota. No bills were discovered in Mitchell.  Anyone who suspects a fake bill should contact Brookings Police immediately. For more crime stories from MitchellNow.com, click here