Tampering with physical evidence

The alteration, destruction or concealment of any physical evidence to be used in an official proceeding for the purpose of altering its outcome is a crime.

The most noteworthy of cases of tampering with evidence is President Nixon's destruction and alteration of tape recordings of White House meetings. Vital documentary evidence in a double murder case in the UK had been destroyed in what may have been a mistaken instance of a cleaning up of a police property store.