2.66 False Declaration (Perjury) Before a Court or Grand Jury / 18 U.S.C. Sec. 1623(a) is a federal offense that occurs when a person knowingly makes a false statement under oath in a court or grand jury proceeding. Perjury is punishable by up to 5 years in prison and/or a fine of up to $250,000. There are two types of perjury offenses under 18 U.S.C. Sec. 1623(a): 1) Making a False Statement: This offense occurs when a person knowingly makes a false statement under oath in a court or grand jury proceeding. 2) Concealing a Material Fact: This offense occurs when a person knowingly conceals a material fact from a court or grand jury proceeding.