Money laundering laws doesn't require that the money be proceeds of crime. It only requires that you do things in an attempt to obscure the source of the money.

For example structuring cash deposits. If you have a pile of legitimate cash, say through a cash business (you pay all taxes), but you intentionally make multiple $9,000 deposits to avoid generating a CTR (currency transaction report for cash deposits over $10,000), congrats, you violated money laundering laws.