In the United States, the crime of witness tampering in federal cases is defined by statute at , "Tampering with a witness, victim, or an informant". The punishment for such an offense is up to 20 years if physical force was used or attempted, and up to 10 years if physical force was only threatened. The tampering need not have actually been successful in order for it to be criminal.
One of the better known cases involving section 1512 is Arthur Andersen LLP v. United States, decided by the U.S. Supreme Court in May 2005. The Supreme Court ruled that section 1512 had been misinterpreted by the Fifth Circuit Court of Appeals, and reversed the decision of the lower court which had found the firm guilty of violating the section. The issue had, to some extent, become moot, because in 2002 the firm had all but dissolved as a result of prosecution on this criminal charge.
Buddy Cianci was indicted on a charge of witness tampering.