What are marked bills?

Answer:

Marked bills are U.S. currency police officers use when they try to buy illegal items, usually drugs. The police record the serial numbers of the bills before they use them, often by photocopying the bills.

After the purchase, the police try to make a quick arrest. If the suspect is caught with the marked money on him, it makes for a strong case.

First answer by Philip6. Last edit by Philip6. Contributor trust: 42 Question popularity: 4 [recommend question].