One of the most important lessons to be learned from the trial of Ross Monaghan for the murder of Kevin "The Gerbil" Carroll in an Asda car park in Glasgow, which ended in an acquittal, is that forensic experts should be independent and maintain a professional distance from the police.
In the words of Derek Ogg, QC, the advocate who defended Mr Monaghan, there should be a robust firewall between the police and forensic science.
The reasons for such a firewall became clear during Mr Monaghan's trial, when the court heard a forensic expert working at the Scottish Police Services Authority (SPSA), which now falls under the Scottish Police Authority (SPA), filed a report stating that a single particle of firearms discharge residue found at Mr Monaghan's home was similar to that used in cartridges recovered from the crime scene. But it was also revealed at the trial that the expert reached this conclusion at the request of a detective superintendent involved in the investigation.
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Such interference in what should be an independent service to the criminal justice system clearly risks a miscarriage of justice, and the trial judge Lord Brailsford said he found the expert's report disturbing. The details of what happened have been investigated by the Home Office Forensic Science Regulator, which monitors standards for the provision of forensic services to the criminal justice system, although it will be some time before its report will be made public on the grounds that the Crown Office believes a future prosecution could be put at risk.
That decision is questionable - the public deserve to know what mistakes were made in the investigation of Kevin Carroll's murder - but in the meantime Mr Ogg is right to raise the issue of how a proper distance can be maintained between forensic experts and the police.
In England and Wales the distance is maintained by basing forensic services and law enforcement in different buildings, and Mr Ogg believes the problems in the Carroll case might have been avoided if Scotland followed this example. Instead, the main unit of Scotland's forensic science service has just moved in to the Scottish Crime Campus in Gartcosh along with police colleagues - a set-up Mr Ogg fears could result in the pressure seen in the Carroll being brought to bear again on forensic experts.
In response, Tom Nelson, the director of SPA Forensic Services, has pointed out that the organisation has its own dedicated wing on the campus, although the scientists do share common areas with prosecutors and police officers. Mr Nelson believes this allows the scientists to work more closely with their colleagues while maintaining their autonomy.
Whoever is right, Mr Nelson or Mr Ogg, the arrangements at Gartcosh are unlikely to change, but the report into the trial (redacted in places if necessary) could still make a useful contribution to the debate. It should be made public as soon as possible to help avoid a repeat of the serious mistakes that were made in the Carroll case.