In the United Kingdom the use of assisting offenders is enabled by the Serious Organised Crime and Police Act 2005 (SOCPA), the relevant sections of which came into force in 2006.
Section 72[2] of the SOCPA allows a specified prosecutor to grant an undertaking to an assisting offender that information will not be used against that person.
Section 74[4] of the SOCPA allows a specified prosecutor to seek a review of a previously sentenced prisoner who has entered an agreement to assist the prosecution or investigation of other criminals in exchange for a reduced sentence.
In 2007 Rhys Jones was shot dead in Liverpool as part of a gang related incident.
One of the suspects was later arrested in possession of a firearm and became an assisting offender, giving evidence for the prosecution.