Wasn't it that they chose not to try Sarah for joint enterprise, because if they did and she was found innocent, then it'd somehow ruin CPS chances of prosecuting her of such in the future when more evidence comes to light?
I don't think so, they can get a new trial after an acquittal if new evidence comes to light.
see Double Jeopardy (wiki) :
Double jeopardy - Wikipedia
England and Wales
Double jeopardy has been permitted in
England and Wales in certain (exceptional) circumstances since the
Criminal Justice Act 2003.
Post-2003
Following the
murder of Stephen Lawrence, the Macpherson Report recommended that the double jeopardy rule should be
abrogated in murder cases, and that it should be possible to subject an acquitted murder suspect to a second trial if "fresh and viable" new evidence later came to light. The
Law Commission later added its support to this in its report "Double Jeopardy and Prosecution Appeals" (2001). A parallel report into the
criminal justice system by
Lord Justice Auld, a past
Senior Presiding Judge for England and Wales, had also commenced in 1999 and was published as the Auld Report six months after the Law Commission report. It opined that the Law Commission had been unduly cautious by limiting the scope to murder and that "the exceptions should [...] extend to other grave offences punishable with life and/or long terms of imprisonment as Parliament might specify."
[35]
Both
Jack Straw (then
Home Secretary) and
William Hague (then
Leader of the Opposition) favoured this measure.
[36] These recommendations were implemented—not uncontroversially at the time—within the
Criminal Justice Act 2003,
[37][38] and this provision came into force in April 2005.
[39] It opened certain serious crimes (including murder,
manslaughter,
kidnapping,
rape,
armed robbery, and serious
drug crimes) to a retrial, regardless of when committed, with two conditions: the
retrial must be approved by the
Director of Public Prosecutions, and the
Court of Appeal must agree to quash the original acquittal due to "new and compelling evidence".
[40] Then Director of Public Prosecutions,
Ken Macdonald QC, said that he expected no more than a handful of cases to be brought in a year.
[41]
Pressure by Ann Ming, the mother of 1989 murder victim Julie Hogg—whose killer, William Dunlop, was initially acquitted and subsequently confessed—also contributed to the demand for legal change.
[41] On 11 September 2006, Dunlop became the first person to be convicted of murder following a prior acquittal for the same crime, in his case his 1991 acquittal of Hogg's murder. Some years later he had confessed to the crime, and was convicted of
perjury, but was unable to be retried for the killing itself. The case was re-investigated in early 2005, when the new law came into effect, and his case was referred to the Court of Appeal, in November 2005, for permission for a new trial, which was granted.
[41][42][43] Dunlop pleaded guilty to murder and was sentenced to life imprisonment, with a recommendation he serve no less than 17 years.
[44]
On 13 December 2010, Mark Weston became the first person to be retried and found guilty of murder by a jury (Dunlop having confessed). In 1996 Weston had been acquitted of the murder of Vikki Thompson at
Ascott-under-Wychwood on 12 August 1995, but following the discovery in 2009 of compelling new evidence (Thompson's blood on Weston's boots) he was arrested and tried for a second time. He was sentenced to life imprisonment, to serve a minimum of 13 years.
[45]
In December 2018, convicted paedophile
Russell Bishop was also retried and found guilty by a jury for the
Babes in the Wood murders of two 9-year-old girls, Nicola Fellows and Karen Hadaway, on 9 October 1986. At the original trial in 1987, a key piece of the prosecution's case rested on the recovery of a discarded blue sweatshirt. Under questioning, Bishop denied that the sweatshirt belonged to him, but his girlfriend, Jennifer Johnson, alleged the clothing was Bishop's, before she changed her story in the trial, telling the jury she had never seen the top before.
[46] Attributed to a series of blunders in the prosecution's case, Bishop was acquitted by the jury after two hours of deliberations.
[46] Three years later, Bishop was found guilty of the abduction, molestation, and attempted murder of a 7-year-old girl in February 1990.
[47] In 2014, re-examined by modern forensics, the sweatshirt contained traces of Bishop's DNA, and also had fibres on it from both of the girls' clothing.
[47] Tapings taken from Karen Hadaway's arm also yielded traces of Bishop's DNA.
[47] At the 2018 trial, a jury of seven men and five women returned a guilty verdict after two-and-a-half hours of deliberation.
[46][47]
On 14 November 2019, Michael Weir became the first person to be twice found guilty of a murder. He was originally convicted of the murder of Leonard Harris and Rose Seferian in 1999, but the conviction was quashed in 2000 by the Court of Appeal on a technicality. In 2018, new
DNA evidence had been obtained and palm prints from both murder scenes were matched to Weir. Twenty years after the original conviction, Weir was convicted of the murders for a second time.
[3]