Misprision of treason is an offence found in many common law jurisdictions around the world, having been inherited from English law. It is committed by someone who knows a treason is being or is about to be committed but does not report it to a proper authority.
Under Australian law a person is guilty of misprision of treason if he:
(a) receives or assists another person who, to his or her knowledge, has committed treason with the intention of allowing him or her to escape punishment or apprehension; or
(b) knowing that another person intends to commit treason, does not inform a constable of it within a reasonable time or use other reasonable endeavours to prevent the commission of the offence.
The penalty is life imprisonment.
Under section 50(1)(b) of the Canadian Criminal Code, a person is guilty of an offence (although it is not described as misprision) if: "knowing that a person is about to commit high treason or treason [he] does not, with all reasonable dispatch, inform a justice of the peace or other peace officer thereof or make other reasonable efforts to prevent that person from committing high treason or treason."
The maximum penalty is 14 years.
Under section 3 of the Treason Act 1939 a person is guilty of misprision of treason if "knowing that any act the commission of which would be treason is intended or proposed to be, or is being, or has been committed, [he] does not forthwith disclose the same, together with all particulars thereof known to him, to a Justice of the District Court, or an officer of the Gárda Síochána, or some other person lawfully engaged on duties relating to the preservation of peace and order."
Section 76(b) of the Crimes Act 1961 provides that any person who "knowing that a person is about to commit treason, fails without reasonable excuse to inform a constable as soon as possible or to use other reasonable efforts to prevent its commission" is guilty of an offence.
A person guilty of this offence is liable to imprisonment for a term not exceeding seven years.
Russia has no specific offence of misprision. However Article 275 of the Criminal Code of Russia encourages people to come forward with information by providing them with a statutory defence to treason and other offences:
A person who has committed crimes stipulated in this Article, or by Articles 276 and 278 of this Code, shall be relieved from criminal responsibility if he has facilitated the prevention of further damage to the interests of the Russian Federation by informing the governmental authorities of his own free will and in due time, or in any other way, if his actions contain no other corpus delicti.
Misprision of treason is an offence under the common law of England and Wales and the common law of Northern Ireland. By statute, the offence of misprision of treason under the common law of England has been made an offence which is cognisable under the law of Scotland. This offence was formerly known as misprision of high treason in order to distinguish it from misprision of petty treason, before that offence was abolished along with its parent offence in 1828.
The crime is committed where a person knows that treason is being planned or committed and does not report it as soon as he can to a justice of the peace or other authority. The offender does not need to consent to the treason; mere knowledge is enough. Concealment of treason was itself a treason at common law until the Treason Act 1554 deemed it merely misprision of treason, which was a felony.
In R v. Tonge (1662) 6 State Tr 225, it was said that:
Where a person knowing of the design meets with the others and hears them discourse of their traitorous designs and says or acts nothing; this is high treason in that party, for it is more than a bare concealment, which is misprision. But if a person not knowing of their design before, come into their company and hear their discourses, and say nothing, and never meet with them again at their consultations, that conduct is only misprision of high treason.
(For more information about the "Tonge Plot", see Intelligence and Espionage in the Reign of Charles II, 1660-1685 (Marshall, 1994)).
Similarly, in R v. Walcott (1683) 9 State Tr 519 at 553, Pemberton, LCJ. said:
For a man to hear of treason accidentally or occasionally and conceal it is but misprision, but if a man will be at consult where treason is hatched and will then conceal it he is guilty of treason therein.
It is punishable by imprisonment for life.
In the United States, misprision of treason is a federal offense, committed where someone who has knowledge of the commission of any treason against the United States, conceals such knowledge and does not inform the President, a federal judge, a State Governor, or a State judge (18 U.S.C. § 2382). It is punishable by a fine and up to seven years in federal prison. It is also a crime punishable under the criminal laws of many states.