Truck drivers for a hauling company, while loading a desk, found a $100 bill that had fallen out of the desk. They agreed to get it exchanged for small bills and divide the proceeds. En route to a bank, one of them changed his mind and refused to proceed with the scheme, whereupon the other pulled a knife and demanded the bill. A police officer intervened. It turned out that the bill was counterfeit money. What crimes have been committed?