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Drug driving demand exceeds forensic analysis capacity

Published : 21/06/2022 07:23:40

More than 5,600 drug driving blood samples have been tested since 2019 when new legislation was introduced in Scotland, making it an offence to drive whilst over the limit for certain drugs.

In response to the new offence, which came into force in October 2019, Police Scotland commenced roadside mouth swab testing for cannabis and cocaine on any motorist they suspected of being impaired whilst driving under the influence of drugs, or who was suspected of driving with a level of drugs in their blood above the allowed limit. The police can request a blood sample for testing and analysis for any of the 17 drugs specified in regulations.

Testing and analysis on blood samples are carried out by the Scottish Police Authority’s Forensic Services, currently supported by accredited commercial forensic science providers. In 2019, drug driving analytical services were set up by Forensic Services and funded by the Scottish Government to test up to 1,000 cases per annum. This anticipated demand was estimated by a working group involving Forensic Services, Police Scotland, Crown Office and Procurator Fiscal Service and the Scottish Government.

Demand has been more than twice what was estimated originally and the Forensic Services laboratory set up to support demand has been reporting sustained high levels of demand for drug driving testing to the Authority since 2020. The impact of this demand has risen to the point where, as at 20 May 2022, 386 cases cannot be pursued to prosecution because of forensic testing and analysis delays and having reached the current statutory 12-month time limit.

Forensic Services have been working closely with Police Scotland, the COPFS and the Scottish Government to manage cases amidst the continued high levels of demand.

At a meeting on Thursday (23 June) the Scottish Police Authority will consider a report on behalf of the justice system, presented by the Director of Forensic Services to discuss the challenges.

Testing to date has focused on the highest risk cases including those involving fatalities or collisions to ensure incidents that have caused the most harm are prioritised. The 386 cases that have not been completed in time are primarily the lowest risk cases with no fatalities and only 3 cases recording any injury.  

Forensic Services has received £681,000 of additional investment from the Scottish Government to build its capacity by outsourcing cases to accredited commercial forensic science providers. A further £370,000 has been committed this year. This is on top of Scottish Government funding to create the original drug-driving service.

Efforts to address the continued demand since the testing was introduced in 2019, include:

  • Additional investment of more than £1m from the Scottish Government to support the outsourcing of approximately 30% of cases to commercial forensic service providers;
  • Enhancing instrumentation and processes which led to an increase of in-house capacity by 50%;
  • Also, coronavirus legislation extended the statutory reporting period from 6 to 12 months.

The reported number of cases have been compiled and examined by a correlation process across Police Scotland, Forensic Services and COPFS systems and cover the period up to 20 May 2022. Further cases are anticipated to reach the statutory limit in the immediate months ahead. Forensic Services, Police Scotland and the COPFS are currently reviewing the upcoming cases to identify and prioritise further cases at risk of reaching the statutory limit.

Reporting on the issue to the Scottish Police Authority, Fiona Douglas, Director of Forensic Services said:

“Demand for drug-driving toxicology analysis has far outstripped what was estimated when the new offence was introduced in Scotland in 2019. To date, more than 5,600 cases have been processed for testing and analysis. We have been working hard to manage a continued demand supported by additional investment from the Scottish Government to help increase laboratory capacity and outsource a number of cases.

“Unfortunately the current backlog and continued high demand have resulted in drug-driving cases reaching or coming too close to the time limit to be progressed to prosecution. This is a deeply regrettable situation and I want to apologise and reassure the public and our partners that our laboratory staff are working tirelessly and remain committed to processing samples in a timely manner. We are also working closely with Police Scotland, COPFS and the Scottish Government to manage and minimise risks and to develop a sustainable system-wide solution that can meet future demand and mitigate against cases reaching their statutory time limit as a result of forensic testing and analysis in the future.”

Speaking ahead of the Authority meeting, Martyn Evans, Chair of the Scottish Police Authority added:

“The demand for drug driving analysis and the efforts to manage and reduce a current backlog have been reported regularly to the Authority. This pressure has now risen to the level where the justice system has seen an impact on the ability to prosecute around 7% of cases. We are deeply concerned that 386 drug driving cases cannot be progressed to prosecution due to testing and analysis not being processed within an adequate timeframe. It is a serious failure.

“A Gold Command Group, involving all partners, was established in May to examine compile and correlate the affected cases, review the drug driving testing process and ongoing prioritisation. This Group is considering Police Scotland and Forensic Services processes and the actions in train to minimise further cases from reaching their statutory time limit in the future. In addition, I have asked and HMICS has confirmed that it will carry out, a review of the end-to-end process for obtaining, analysing and reporting drug driving blood sample results in order to support criminal proceedings. This review will consider the issues that have led to cases reaching their statutory time limit before they can be progressed to prosecution. It will also look at whether the mitigations in place are having an impact and if the immediate issues have been resolved as far as practicable.

“There is no doubt that demand for this service has been underestimated. The Authority has a clear interest in the scale and effectiveness of public policy, investment in and approaches to tackling drug driving. We will continue to work closely with Forensic Services, the Scottish Government, Police Scotland, COPFS and HMICS to develop and agree a sustainable model for this service while minimising the ongoing risks associated with the current capacity issues.”

Assistant Chief Constable Mark Williams, head of Operational Support at Police Scotland added: “We are committed to detecting and taking action against those who take drugs and drive.

“Being able to use roadside drug wipes has significantly enhanced our ability to detect those responsible and keep the public safe. Despite the current challenges around testing capacity, Police Scotland’s commitment remains unchanged.

“We are working closely with the SPA, Crown Office and Scottish Government to find effective solutions.”

On behalf of the Crown Office and Procurator Fiscal Service, Deputy Crown Agent Stephen McGowan said:

“Scotland’s prosecutors are working with justice partners on keeping people safe from the harm caused by those driving under the influence of illegal drugs.

“We have processes in place to ensure that, while these pressures exist on the testing regime, appropriate prosecutorial action is taken in as many cases as possible.”



The Scottish Police Authority is responsible for providing Forensic Services to Police Scotland and the COPFS in Scotland. This process is accredited to the recognised laboratory standard ISO 17025 by UKAS – the UK Accreditation Service.

More than 5,600 tests have been conducted on drug driving cases since October 2019.

The 386 cases to 20 May 2022 being reported to the Authority are Section 5A and Section 4 offences under the Road Traffic Act 1988.

For more information on the drug driving rules introduced in October 2019, you can read the Scottish Government’s Factsheet here.