Decoy in White M Squad : Season 2 Episode 37

In a factory, an accountant counting money notices two bills have the same serial number. He tells the president and a federal agent, who thanks the teller and says if he finds any more to notify him. When the teller leaves it becomes clear that the man is not a federal agent, but a someone who brings money to the bank president for laundering. The businessman demands a bigger percentage of the profits. Later that night he is killed and the murder is assigned to Frank. The man's wife says he was a gambler and there is more to the case than a simple robbery homicide.