The man used a procedure in which he submerged a white note into a bath of chemicals to create a print from an existing note. The technique is called Wash Wash. He then sold the notes and the chemicals, but later the buyer would discover that the notes could easily be distinguished from the real thing.
Examined by federal police the suspect was found to be in possession of 2,500 sheets of paper plus bottles of chemicals. He’s been arrested and his goods impounded.