IRS Criminal Investigation (CI) is comprised of approximately 4,400 employees worldwide, approximately 2,600 of which are special agents whose investigative jurisdiction includes tax, money laundering and Bank Secrecy Act laws. While other federal agencies also have investigative jurisdiction for money laundering and some bank secrecy act violations, IRS is the only federal agency that can investigate potential criminal violations of the Internal Revenue Code.
Not everyone is intentionally doing something wrong when it comes to filing taxes. In some cases, it is simply a lack of understanding of U.S. rules and regulations. If an immigrant has been in the U.S. for 180 days, they are required to report to U.S. authorities that they have a foreign account and become subject to U.S. taxation.