6 Dropped Drug Driving Cases and What We Can Learn From Them

6 Dropped Drug Driving Cases and What We Can Learn From Them

A positive roadside swab or a laboratory result showing a driver is "over the limit" can make a prosecution seem inevitable. However, that is not necessarily the case. Drug driving proceedings depend on a sequence of forensic and procedural stages, including the roadside test, collection of the blood specimen, laboratory testing, and disclosure of the evidence to the defence. If one part of that process breaks down, the prosecution may fail before a verdict is ever reached.

Drug Driving Solicitors has acted for clients in dozens of drug driving matters that concluded through discontinuance, dismissal, or acquittal. The following six cases come from the firm's own case history and illustrate the particular issue that caused each prosecution to fall apart.

1. The Roadside Officer's Account Could Not Be Reconciled With the Test R v Lewis, Manchester Magistrates' Court [Case Dismissed, February 2023]

In Mr Lewis's case, the arresting officer stated that the roadside drug test displayed a "blue line" indicating cocaine. That description did not correspond with the way the device actually shows a positive result, which is through two red lines. There were also inconsistencies elsewhere in the officer's account concerning which drug had supposedly produced the positive reading. During cross-examination at trial, those contradictions became clear. The prosecution ultimately accepted that it could no longer establish that the roadside test had been positive, undermining the legal justification for requiring a blood specimen. No additional evidence was then offered.

Why this is important: both roadside drug testing and the officers responsible for recording the results are open to challenge. Even apparently minor inconsistencies in an officer's description of the test may become significant enough to weaken the prosecution's case.

2. The Blood Sample Was Too Small for Reliable Testing R v CH, Bexley Magistrates' Court [Case Discontinued, November 2020]

Mr H arranged for part of his own blood specimen to be examined by an independent forensic toxicologist. The expert reached a clear conclusion: the quantity of blood available was insufficient to conduct a valid analysis. After that finding was provided to the Crown Prosecution Service together with a formal defence statement, the prosecution discontinued the case approximately one week before trial.

Why this is important: strict requirements apply to the quantity, handling, and division of blood specimens. Having the defendant's own portion independently analysed can reveal defects that were not identified by the prosecution laboratory.

3. A Legitimate Medical Explanation Was Not Properly Evaluated R v Franklin, Cambridge Magistrates' Court [Case Discontinued, April 2022]

Mr Franklin faced a charge of failing to provide a specimen after informing police that he suffered from a needle phobia. Where a person raises a potential medical explanation for being unable to provide a sample, the law requires consideration by a medical professional to determine whether it amounts to a reasonable excuse. In this case, no medical professional was brought in to carry out that assessment. An expert later reviewed Mr Franklin's medical records, consulted with him, and confirmed that the phobia was genuine. In light of that evidence and the earlier procedural failure, the prosecution discontinued the matter before trial.

Why this is important: a charge of "failure to provide" does not automatically establish an offence. When a genuine medical reason is raised, it should be properly assessed by the police, and a failure to obtain that assessment can significantly damage the prosecution case.

4. The Laboratory Lost the Required Accreditation During Proceedings R v LT, Llandudno Magistrates' Court (March 2021)

A number of cases handled by the firm involved the same critical issue: the laboratory responsible for analysing blood specimens had lost its UKAS accreditation for the specific testing required under section 5A of the Road Traffic Act 1988. In Mr T's matter, the problem only became apparent once the prosecution served its own analytical data pack and that material was reviewed. After it was confirmed that the relevant accreditation had been lost, the reliability of the laboratory analysis came into question. On the trial date, the prosecution requested an adjournment, but the court refused the application and no evidence was offered.

Why this is important: a laboratory result showing someone "above the limit" depends on the reliability and proper accreditation of the facility that produced it. Where the laboratory lacked the necessary accreditation for the test, the reported figure may not withstand scrutiny in court.

5. The Prosecution Failed to Meet Repeated Disclosure Deadlines Mr Sharpe [Case Discontinued, October 2018]

After Mr Sharpe pleaded not guilty, the court established a timetable requiring the prosecution to provide its forensic report and the supporting material. That deadline passed without compliance. At a later hearing, further directions were issued, but those deadlines were missed as well. When the case reached a preliminary hearing only a few weeks before trial, the prosecution had still not complied with the disclosure requirements. Rather than attempting to continue without the evidence being properly in order, the prosecution discontinued the case.

Why this is important: the Criminal Procedure Rules impose genuine duties on the prosecution to provide evidence within the required timeframes. Repeated non-compliance is more than a minor procedural issue. Courts have refused to allow prosecutors to rely on evidence served too late, and without that evidence a prosecution may be unable to continue.

6. The Blood Reading Was Below the Legal Limit R v Singh, Swindon Magistrates' Court [Case Discontinued, December 2022]

Mr Singh's case presented an unusual set of circumstances. His blood specimen produced a result below the legal limit, yet he was still prosecuted for the separate offence of driving while unfit through drugs. The allegation relied in part on statements he had made during a police interview several months later. Professor Atholl Johnston was instructed as an expert and concluded that the concentration found in Mr Singh's blood did not correspond with the amount he had described taking and was unlikely to have had much effect on him. A separate error in the hospital paperwork was also identified. Taken together, these issues ultimately led the prosecution to discontinue the case.

Why this is important: the existence of a charge does not necessarily mean the supporting evidence establishes the alleged offence. A result below the legal limit, together with expert analysis of what the detected level would realistically mean for a person's ability to drive, may expose weaknesses in a case that initially appears much stronger.

What These Cases Have in Common

These six prosecutions did not end simply because the police reconsidered their position. Each case involved an identifiable and demonstrable problem, whether that was inconsistent officer evidence, an inadequate blood specimen, a medical reason that was never properly assessed, a laboratory without the required accreditation, missed disclosure deadlines, or a blood result that did not support the allegation being pursued. In each instance, identifying the issue depended on a defence team knowing which parts of the evidence and procedure required close examination.

For anyone accused of drug driving, the circumstances surrounding the stop, the collection and testing of the specimen, and the evidence supporting the allegation may be more significant than the figure printed on a laboratory report. Consulting a specialist solicitor at an early stage can help determine whether any comparable evidential or procedural issue may affect the case.

This article provides general information only and should not be treated as legal advice. The outcome of every case depends on its individual facts.