Destruction of evidence
Shredding of official documents
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.