Police are reviewing security video, hoping to identify a man believed to have passed counterfeit currency at a Warren drug store.

The manager of the Elm Road Walgreens told an officer that a customer handed a clerk two older looking $100 bills at the store last Friday.

According to the manger, the employee checked the bills with a counterfeit detection pen, and they appeared to be genuine.

The manager didn’t find out for another four days that the bills were phony.

Police were given a description of the suspect and continue to investigate.

According to the Federal Reserve, counterfeit detection pens are not always accurate and may give you false results.

The best way to determine whether a note is genuine is to rely on the security features, such as the watermark and security thread.

If you end up with a counterfeit note, you will lose that money. A counterfeit note cannot be exchanged for a genuine one, and it is illegal to knowingly pass counterfeit currency.