Can I Challenge A Drug Driving Blood Test Result?

Can drug driving blood tests be wrong? Learn how to challenge results and build a strong legal defence.

If you’ve been charged by the police , you may feel uncertain about what’s happening next. You may think that you have no choice but to plead guilty, just because the charge sheet accuses you of being over the legal limit. This is not the case.

In this blog we’ll explain what the blood result means, what the prosecution has to prove and how the blood results aren't always as accurate as they seem.

Real Case Example: Case Dropped Due to Blood Test Issues

A client was charged with being over the legal limit for BZE (a cocaine metabolite). The case was handled by our specialist solicitor John Fairhurst.

The defendant entered a not guilty plea. John requested full disclosure of evidence from the CPS, which included blood test room footage. When John carefully reviewed the footage, the sample itself was not visible.

However, from the audio, the healthcare professional made certain comments during the blood taking procedure. These suggested multiple samples may have been taken.

Detailed legal submissions were made to the CPS, relying on case law including Dear v DPP.

👉 The prosecution discontinued the case.

This defence was not obvious at first — it was identified through careful, specialist analysis of the evidence.

Randox and Trimega

In 2017, there was suspected data manipluation at Randox Testing Services and, later, Trimega Laboratories. This resulted in Randox losing its accreditation to test samples for the police. Cases affected including drink and drug driving cases involving blood samples. This led to criminal investigations involving seven scientists that were suspected of manipulating data. Many affected cases resulted in the re-testing of samples. Others resulted in charges being withdrawn.

More information can be found at: https://www.gov.uk/government/publications/regulators-notification-07-2024-suspected-data-manipulation-at-randox-testing-services-and-trimega-laboratories/regulators-notification-07-2024-suspected-data-manipulation-at-randox-testing-services-and-trimega-laboratories-relating-to-toxicology-testing-acc

Synlab

In December 2020, Synlab (subcontracted by Key Forensic Services) found that there had been issues with the analysis of samples in drug driving cases. This meant that hundreds of blood results were deemed unreliable. As many people had been convicted based on these results, this led to many people having to appeal convictions to have their convictions quashed. The most shocking part is that many people had already served lengthy driving disqualifications before this was uncovered.

More information can be found at: https://news.npcc.police.uk/releases/review-of-drug-driving-samples-analysed-by-synlab-laboratory-services-limited