Have you ever handed a cashier a $20 bill and watch as they make a mark on it with a pen? They're using a counterfeit pen that contains iodine to tell if the bill is real or not. If a black mark appears, it's fake. In the case of counterfeit money that police warn is being circulated in Sanford and Springvale, there's an even easier way to detect it.

Sanford Police posted on their Facebook page that there are suspects going into convenience stores in the area and trying to pass off fake $20 bills as real. Though they look authentic, upon closer inspection, there's a telltale sign that they are fake as shown by similar fake money in this photo by ebay seller keiez88.

keiez88 via ebay

You can see they are clearly marked "For Motion Picture Use Only" which is easy to stop when looking for the marking, but not noticeable when they are used in films. Sanford Police say mostly $20 bills marked with "For Motion Picture Use Only" or "Copy" are the counterfeit money being passed off as real.

Police ask that cashiers in the area take close look at $20 bills that they receive to see if the "For Motion Picture Use Only" stamp on them to make sure it's the real deal. If a cashier should receive one of these bills, contact Sanford Police.

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