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Can the police drug test you for no reason?

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Can the police drug test you for no reason?




If you have been stopped by the police and asked to provide a sample for a drug test, whether it be a roadside drug swab or a specimen of blood, you may be wondering what your rights are in regards to police powers and if you have to comply.


Over 16 years of specialising solely in drink and drug driving, we have been asked time and time again.


"Can the police drug test you for no reason?"



In this short article, we hope to shed light on this issue and provide you with an insightful understanding of your rights in regards to the police requesting a drug test.

The short answer to this question would be yes. Under the Road Traffic Act 1988, Section 168, any constable in uniform has the right to stop a motor vehicle on a road, and failure to do so by a motorist would result in an offense. This is also otherwise known as a 136-stop. Although this allows the constable the right to stop your vehicle, it does not grant the right to conduct a roadside test such as a "drug swab."


Reasonable Suspicion



In order to conduct the preliminary drug tests, the officer must have "reasonable suspicion" to believe that you are under the influence of drugs.

Examples of "reasonable suspicion" could be:


  • Erratic Driving 

  • Running a red light or failing to stop at a stop sign

  • Slurred Speech

  • Bloodshot or glazed eyes

  • Smell of alcohol or cannabis

  • The sight of drug paraphernalia


If no reasonable suspicion is evident theoretically, it is not within the rights of the officer to conduct the preliminary reading, but many times we see reasonable suspicion as a clause thrown around loosely by officers. In cases where the motorist has been involved in an accident, collision, or committed a traffic offence such as running a red light, reasonable suspicion is not necessary as there is a plausible reason for impairment.

As well, officers may set up roadside stops during holiday periods where they exercise the 136 stop in order to stop motorists displaying any signs of impairment and subject them to testing.


Police Procedure



We often find that the police will state the reason for erratic driving and stop your vehicle, then the officer will make an arrest and conduct the preliminary drug test procedure. Usually this will involve the officer asking you for a sample of saliva and allowing them to screen for THC, the primary metabolite found in cannabis, and benzoylecgonine, which is the primary metabolite found in cocaine. It is important to note that the initial "Drug Swabs'' are not court admissible evidence and are only used in order for the police to prove that the drug was in your system.

The swabs are considered a preliminary drug test and do not provide an indication of impairment as they do not measure whether the concentration of metabolite found in the sample was above the prescribed drug driving limit at the time of testing. If you fail to provide an initial drug swab or F.I.D., you will more than likely be arrested and taken back to the police station, where you will undergo further testing.


The field impairment test



You may instead be subject to a field impairment test, which is an assessment used by the police to prove impairment and whether an individual is unfit to drive. It is important to note that the field impairment test can only be conducted by an officer who has undergone specific training and received accreditation in order to conduct the procedure.

If the officer has not, then defending your case is as easy as us requesting the officer's training certificates on your behalf. If they're not provided, then the procedure conducted is invalid, and subsequently, any charges will be dropped.

For more information on the FID, visit here.


The evidential blood sample 



If you have failed to cooperate with the preliminary testing procedure or tested positive, you will be taken back to the police station and asked for a sample of blood or urine for analysis. In most cases, you will be asked to provide two samples of blood. You will also be told at this point that failure to do so will result in an offence of failure to provide. If you were to plead guilty to an offence of failure to provide, you could face consequences such as a criminal record, a large fine, and a mandatory one-year driving disqualification.

We find that due to the time-sensitive nature of drug driving offences, the police rush the procedure and subsequently make mistakes, which we capitalise on. These mistakes could be incomplete or invalid MGDDGF, not providing a statutory warning, preservation issues in regards to the sample, incorrect testing calibrants used, and the list goes on. To view our defences for drug driving, please visit here.


Seek legal advice from a specialist.



At Parnell and Peel, we know how challenging and stressful being charged with drug driving can be. We recognise that this is a time of uncertainty and concern in your life, and we aim to diminish the burden. We provide you with unwavering support throughout the lifecycle of your case and hope to provide our clients with ease knowing that their case is in good hands.

Our team of specialist drink driving solicitors and advocates leverages our decades of experience to carefully construct a strategy to mitigate any personal, financial, or professional consequences you may face as a result of your offense.


We believe people make mistakes, and everyone has a right to first-rate, exemplary legal representation.


Contact us for a chat at 0330 341 1690 .