Four cases under investigation

Counterfeit bills have been popping up around Andover since the latter half of November.
So far, there are four cases of counterfeit that the Andover Police Department has been investigating.
"That's an uptick for us," APD Lieutenant in Investigation Daimon Cundiff said.
Out of those four cases, one has led to the arrest of an adult male. The remaining three cases are still under active investigation, and no arrests have yet been made for those.
"Most of the bills could be detected by someone well-versed in U.S. currency, but some of the bills are making it through the stores and getting to the banks before getting caught," Cundiff said.
The bills could be 20s, 50s or 100s.
"The way they are working is: they go in to make purchases in, like, a retail store – or something of low value. And they'll get change for a larger bill, like a 20 or 50. And that's where they're making their money: from the change," Cundiff said.
Cundiff advises people to be aware of the security strips on the bills that are supposed to have them. He also warns that counterfeit pens may not be effective in detecting fake bills because the pens react to the type of paper the bill is made with – and these counterfeits have apparently been made with thick paper in an attempt to match that of real cash.
People can visit uscurrency.gov to learn about the security features of each dollar bill.