The issue here is under-reporting of one's income, not how you make bank deposits. The $10,000+ reporting requirement by banks to the government is intended to help the Feds track illegal money transactions of things such as drug sales as well as people who have cash earnings (e.g. cars sold for cash) that they are trying to hide from the IRS. If the Baldwins have reported all of their earnings properly to the IRS, then the IRS will not care how that money was deposited in the bank.
Because the Baldwins live in the San Diego area, they are in a place where the IRS and FBI are especially active in looking for patterns of large cash deposits. There is a lot of illegal drug activity there. If they had made only a few cash deposits in one year, that would be no big deal. But to regularly make the deposits for your business in cash, that raises a red flag to the IRS and FBI. They are going to look at whether or not the cash comes from illegal activity, and if not, if all earned income was reported to the IRS. I am not surprised that they are being investigated for doing frequent cash deposits. In order to win their case, they will need to have meticulous bookkeeping showing where the money for the deposits came from and to prove that all of this money was reported as business income to the IRS.
An IRS or FBI investigation can be triggered by any suspicious cash deposits or other bank transactions (e.g. the Stormy Daniels payout). Even people who inherit something of cash value (like a coin collection or jewelry), sell it, and try to hide this money by making a series of small deposits (less than $10,000) into their bank account, may get caught. This practice is called "structuring":
Structuring includes the act of parceling what would otherwise be a large financial transaction into a series of smaller transactions to avoid scrutiny by regulators or law enforcement. Structuring often appears in federal indictments related to money laundering, fraud, and other financial crimes.
Because the Baldwins live in the San Diego area, they are in a place where the IRS and FBI are especially active in looking for patterns of large cash deposits. There is a lot of illegal drug activity there. If they had made only a few cash deposits in one year, that would be no big deal. But to regularly make the deposits for your business in cash, that raises a red flag to the IRS and FBI. They are going to look at whether or not the cash comes from illegal activity, and if not, if all earned income was reported to the IRS. I am not surprised that they are being investigated for doing frequent cash deposits. In order to win their case, they will need to have meticulous bookkeeping showing where the money for the deposits came from and to prove that all of this money was reported as business income to the IRS.
An IRS or FBI investigation can be triggered by any suspicious cash deposits or other bank transactions (e.g. the Stormy Daniels payout). Even people who inherit something of cash value (like a coin collection or jewelry), sell it, and try to hide this money by making a series of small deposits (less than $10,000) into their bank account, may get caught. This practice is called "structuring":
Structuring includes the act of parceling what would otherwise be a large financial transaction into a series of smaller transactions to avoid scrutiny by regulators or law enforcement. Structuring often appears in federal indictments related to money laundering, fraud, and other financial crimes.