Updated

The pen commonly used to identify counterfeit money isn't enough to tell that $100 bills being passed in Central Louisiana are phony. Bank tellers and store clerks need to look at other security features built into every bill, police say.

Counterfeiters have been removing the ink from $5 bills and printing them as $100s, said Alexandria Police Sgt. Lee Leach, who is a financial crimes detective. Because they use the paper from real money, they will pass the pen test, he said.

"Last week, 24 counterfeit $100 bills from businesses in the area were collected," Leach said. "The counterfeiters of this caliber typically move on as the money is passed."

The pen's ink checks for chemicals embedded in currency. "The pen can only tell if the paper is authentic or not ... If the money has been washed and you have a fake $100, it's no good and you're out of money," Leach said.

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Other ways to tell the washed $5s:

—Looking at the face of the bill, tilt the bill so the top edge is down, and see whether the ink in the bottom right corner changes color.

—Check the embedded security thread that runs from the top edge to the bottom edge. If the bill started as a $5, it will read "U.S. five".

—Check the watermark near the right edge of the bill's face; the portrait should match that on the bill.

Embedded security threads also glow different colors under ultraviolet light: blue for $5s, gold-yellow for $10s, green for $20s, gold-yellow for $50s, and red for $100s.

Some businesses won't take any bill larger than a $20. But people counterfeit $20s and $10s, too, Leach said.

Bobbie Abshire, a marketing operations manager for Capital One bank branches in Alexandria, said Capital One received two washed $100 bills in two weeks.

"We have counterfeit detection on currency counters, and it's a good idea for people to look to find Abraham Lincoln's face on a $100 bill," Abshire said. "I was a teller before, and those fake $100 bills look different. They are real good quality, but the color is faded looking."

He said the Police Department will sponsor counterfeit detection classes for businesses.

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