Misprision

 
Misprision is the neglect or wrongful execution of official duties or the concealment of another's crime.

Negative misprision is the concealment of treason or felony. By the common law of England it was the duty of every liege subject to inform the king's justices and other officers of the law of all treasons and felonies of which the informant had knowledge, and to bring the offender to justice by arrest.

Positive misprision is the doing of something which ought not to be done; or the commission of a serious offence falling short of treason or felony, in other words of a misdemeanour of a public character (e.g. maladministration of high officials, contempt of the sovereign or magistrates, &c.). To endeavour to dissuade a witness from giving evidence or to advise a prisoner to stand mute, used to be described as misprisions.

Under an Act of Parliament of 1534, misprision was the crime of refusing to swear an oath acknowledging the King as head of the church.