That's the case I just settled. My client's didn't trust banks (go figure) and kept their cash in a safe. They got most of their cash from a legal action but they couldn't account for all of it because their job was tip based and they couldn't prove their expenses. Long story short, they went to make a large purchase, people got suspicious, and 90% of American currency has cocaine residue (either from being used to snort or simply going through money counters at a bank). Under a few states' laws and the former federal law, known as civil forfeiture, you are guilty until proven innocent. See e.g.
USA v. $124,700. Only property connected with drugs is forfeited, but the raw deal is that innocent people must prove their innocence and guilty people must prove the proportion of their guilt to get the property back.
Double Jeopardy does not apply and so the guilty person that proved his guilt to get his property back has proved the states' later criminal case.
My clients settled for less than their entire amount (like everyone does) because of the uncertainties of trial - they couldn't prove how much money they spent from their legal award and they couldn't completely prove how much they made in their jobs. Further, my clients were minorities and the case was venued in a minority unfriendly county.