Witness tampering is harming or otherwise threatening a witness

Witness

A witness is someone who has firsthand knowledge about an event, or in the criminal justice systems usually a crime, through his or her senses and can help certify important considerations about the crime or event. A witness who has seen the event first hand is known as an eyewitness...

, hoping to influence his or her testimony

Testimony

In law and in religion, testimony is a solemn attestation as to the truth of a matter. All testimonies should be well thought out and truthful. It was the custom in Ancient Rome for the men to place their right hand on a Bible when taking an oath...

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Witness tampering in the USA

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

Arthur Andersen LLP v. United States

Arthur Andersen LLP v. United States, 544 U.S. 696 was a United States Supreme Court case in which the Court unanimously overturned accounting firm Arthur Andersen's conviction of obstruction of justice on the basis that the jury instructions did not properly portray the law Andersen was charged...

, 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

United States Court of Appeals for the Fifth Circuit

The United States Court of Appeals for the Fifth Circuit is a federal court with appellate jurisdiction over the district courts in the following districts:* Eastern District of Louisiana* Middle District of Louisiana...

, 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.

In April 2001, Buddy Cianci was indicted on a charge of witness tampering. In November 2007, Ted Klaudt

Ted Klaudt

Ted Alvin Klaudt is a farmer, rancher, convicted rapist, and former Republican member of the South Dakota House of Representatives from Walker, South Dakota, United States...

 was convicted on counts of witness tampering.

Witness tampering in England and Wales

In England and Wales, witness tampering by unlawful means, such as violence, bribery, threats or improper pressure, is known as Perverting the course of justice

Perverting the course of justice

Perverting the course of justice, in English, Canadian , and Irish law, is a criminal offence in which someone prevents justice from being served on himself or on another party...

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Section 51 of the Criminal Justice and Public Order Act 1994 includes the offences of intimidating a witness and taking revenge on a witness.