What is the double jeopardy law and when does it apply?

DOUBLE jeopardy laws in the UK were scrapped in 2005 following a number of campaigns - most notably that of the family of murdered teenager Stephen Lawrence.

The laws had been on the statute book for over 800 years. But what were they, and which cases did they impact?

What is double jeopardy?

Double jeopardy is the legal principle which says a person cannot be trialled for the same crime twice.

For example, if a defendant charged with assault is found not guilty, that same person cannot be trialled again for the same crime in the same case.

It is designed to protect against judicial tyranny in which citizens could be subject to arbitrary convictions even after a jury had found them innocent.

The principle is widely practiced in democratic countries, most fervently in the US where it is written into the Constitution as the Fifth Amendment.

But it was repealed by the Labour government in the UK in 2005 after senior judges and legal figures called for more nuanced rules to deal with complex crimes.

The Court of Appeal was given the right to allow for a retrial even after an acquittal if "new, compelling, reliable and substantial evidence" comes to light.

What impact did it have on the Julie Hogg murder case?

Dunlop, now 56 made legal history when he was jailed for life for confessing to the murder of Julie, ten years after her death in 1989 - despite the double jeopardy law.

After a 15 year battle from his victim's family, he was eventually jailed for the murder of Julie Hogg in 2006, following two trials which failed to convict the killer.

In 1999, while serving a sentence for a separate crime, Dunlop Bragged to a prison guard that he had murdered Julie - but wouldn't go to prison for it under UK's double jeopardy laws.

He then served six years for perjury, before eventually being jailed in 2006 for Julie's murder following a landmark overturning of the law.

What impact did it have on the Stephen Lawrence murder case?

Stephen Lawrence, 18, was murdered in April 1993 in an evil race hate attack which scarred Britain.

He was killed by a racist gang in Eltham, South East London, in what became one of the most high profile and notorious crimes in modern British history.

The investigation into his killing led to the initial charging of five suspects but they were not convicted.

A public inquiry into the case led by Sir William Macpherson concluded in 1999 the Metropolitan Police was institutionally racist.

Crucially, Sir William recommended double jeopardy be repealed in murder cases where extraordinary evidence later emerges.

A law to carry this out was passed in 2003 and came into effect in 2005.

Two of the original suspects, Gary Dobson and David Norris, were then able to stand trial for murder in 2011, when "new and substantial evidence" became available.

On January 3, 2012, Dobson and Norris were found guilty of Lawrence's murder with minimum terms of 15 years 2 months and 14 years 3 months respectively.

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