Police are warning businesses and consumers about counterfeiters passing bogus $100 bills.
Here's how you can tell if a bill is real or fake.
Counterfeit or prop money as it's sometimes called, is popular online and easy to get. You can buy $10,000 worth of fake money for only $24 on Amazon.
Most prop money is made for movies. Propmoneys.com sells fake money in stacks of anything from fake dollar bills to hundreds. They even sell duffel bags full of fake cash.
So how can you tell whether the money someone gives you is real or fake?
For the scam in Yankton, it's hidden in plain sight. If you look closely, the bill says Motion Picture purposes only, that's obviously fake. A real bill says Federal Reserve Note.
A $100 bill also has two special security features you can see when you tilt it. If the bell changes colors and the 3-D strip moves, it's real.
You can also tell by touch. If the bill feels rough, that's also a good sign it's real.
And any bill $10 dollars or more has a color changing number in the lower right hand corner.
The easiest way to find out whether or not the bill is fake is to buy a cheap and easy to use pen. If you mark the bill and it's real, the mark is yellow or clear. If the mark turns dark brown or black, then you know the bill is fake.
If you would like to take a closer look at what real bills look like, here is a link to the U.S. Currency website.