Plummer, Justin

On 16 December 1998, following a trial at St Albans Crown Court, Justin Plummer was convicted of the murder of Janice Cartwright-Gilbert. He was sentenced to life imprisonment with a minimum term of 16 years.

Ms Cartwright-Gilbert was found dead inside the mobile home she shared with her partner on 28 February 1997. She had been stabbed multiple times and the mobile home had been set on fire. Her body had bruising to the head consistent with stamping.

Mr Plummer was a prolific burglar who had committed a string of burglaries in the local area during January and February 1997. The prosecution case was that Mr Plummer murdered Ms Cartwright-Gilbert during a burglary, attacking her when she disturbed him. The key issue at trial was whether Mr Plummer’s right shoe could be attributed to marks found on Ms Cartwright-Gilbert’s face.

On 17 January 2000, the Court of Appeal rejected an appeal made on Mr Plummer’s behalf. Mr Plummer applied to the CCRC in March 2000 and, in January 2001, the CCRC decided that there was no real possibility that the Court of Appeal would quash his conviction. Mr Plummer re-applied to the CCRC in November 2017.

Following a detailed review, the CCRC decided to refer Mr Plummer’s conviction to the Court of Appeal because new forensic evidence suggested that the expert footwear mark evidence at Mr Plummer’s trial was fundamentally flawed and the jury were misled.

Two of the prosecution experts who gave evidence (one of whom was a dentist and bite marks expert) did not meet the industry standards required to conduct reliable footwear marks comparison.

These experts gave subjective opinions, in persuasive terms, with the appearance of expertise they did not, in fact, possess. In the CCRC’s view, neither expert should have been permitted to give evidence at the trial.

The referral relied, at least in part, on the work of the Forensic Science Regulator (a post created in 2007), developments in the Criminal Practice Direction on expert evidence and a body of case law that primarily post-dated both Mr Plummer’s trial and the CCRC’s first review.

The CCRC concluded that there was a real possibility the Court would find the new evidence and argument, which undermined the expert evidence produced at trial, rendered the conviction unsafe.

The CCRC referred the conviction in February 2021.

The Court of Appeal quashed the conviction in July 2021 and ordered a retrial.