You may want to google how long one should keep documentation on a tax return, as well as how far back IRS can demand paperwork. Hint - sometimes it is unlimited.

Just by the questions you ask, it seems you need to learn something about record keeping and the importance of it, as well as how MS could be viewed by IRS and other government agencies. In order to prove one's innocence, (as separated from other shady characters who are doing the same activities), documentation is needed to provide proof why one could run thru $$$$$$ thru various cards and bank accounts...