-- Criminal Justice Act 2003 allowed the type of appeal for 30 serious offences including murder, manslaughter, rape and terrorism.
-- It is referred to as a 'Double Jeopardy'
-- The DPP has to approve reopening the case.
-- Usually comes about due to advances in DNA techniques.
-- Seen in the conviction of Billy Dunlop for the murder of Julie Hogg (confession).
-- Also Stephen Lawrence murder (DNA and blood samples)