Schoolgirl Billie-Jo Jenkins was bludgeoned to death while she painted the patio doors at the home of her foster family in Hastings, East Sussex.
Sion Jenkins leaving the Old Bailey with his wife after the second trial
In the nine years since her life was cut short at the age of 13 the case has taken numerous twists and turns through the courts.
Here, BBC News outlines a timeline of the legal process:
15 February 1997 - Billie-Jo is found beaten to death with a metal tent peg at the home in Lower Park Road.
2 July 1998 - Foster father Sion Jenkins, then aged 40, is found guilty of murder by a jury at Lewes Crown Court and jailed for life.
8 July 1998 - Mr Jenkins launches an appeal against the conviction.
15 September 1999 - Channel 4's Trial and Error TV programme throws doubt on the conviction, pointing to sightings of a mentally disturbed local man on the day of the murder.
30 November 1999 - First appeal begins, with judges being asked to re-examine a key part of the prosecution's case - the presence of about 150 microscopic spots of blood discovered on Jenkins' clothing.
21 December 1999 - Appeal Court upholds the jury's verdict.
12 May 2003 - Mr Jenkins is given leave to launch a second appeal after the Criminal Cases Review Commission reviews the case.
30 June 2004 - Second appeal begins.
16 July 2004 - Three Court of Appeal judges free Mr Jenkins and order a retrial after quashing the conviction on the strength of new scientific evidence.
20 April 2005 - Retrial begins at the Old Bailey.
11 July 2005 - Jury fails to reach a verdict after hearing evidence for more than two months and and deliberating for 27 hours and 43 minutes. The Crown calls for a new trial.
31 October 2005 - Second retrial begins.
9 February 2006 - Jury in the second retrial fails to reach a verdict on their eighth day of deliberations. The prosecution says it will not seek a further retrial and Mr Jenkins is formally acquitted.