ST. JOSEPH, Mo. (AP) — St. Joseph police say someone has been passing counterfeit $20 bills around town for the past couple of weeks. Detective Richard Shelton says most of the bills have the same serial number, which leads him to believe the counterfeiters are local. At least eight businesses have reported receiving the fake money. The St. Joseph News-Press reports that the manager of a U.S. Oil store says someone tried to use two fake $20 bills last month, but a clerk became suspicious and determined they were counterfeit. The manager says the customer put the bills on the counter and ran. The St. Joseph Police Department is helping the Secret Service investigate because possessing or producing counterfeit money is a federal crime.