Here’s the federal law:
“Making false statements (18 U.S.C. § 1001) is the common name for the United States federal crime laid out in Section 1001 of Title 18 of the United States Code, which generally prohibits knowingly and willfully making false or fraudulent statements, or concealing information, in “any matter within the jurisdiction” of the federal government of the United States, even by mere denial. A number of notable people have been convicted under the section, including Martha Stewart, Rod Blagojevich, Scooter Libby, Bernard Madoff, and former aenron CEO Jeffrey Skilling.”— Wikipedia
Ask Martha Stewart.
Lying to the FBI is at minimum Obstruction of Justice.