Drugs of Abuse


Members of the Department

Anne Franc
CBiol. MSB. >

The Illicit drugs market is constantly changing and so to are drugs of abuse. The traditional drugs like heroin, cocaine, amphetamine, ‘ecstasy’ and cannabis now have stiff competition from a whole host of ‘designer’ drugs (e.g. mephedrone), which were once so called ‘legal highs’ and readily available on the internet , but have now been generically controlled under recent government modifications to the Misuse of Drugs Act. 


Changes in drugs of abuse

Traditional drugs themselves have been subject to change, with sharp decreases in the purity of powdered drugs sold at street level. For example, cocaine powder, which a few years ago may have been sold on the street at a purity of 70% may now have a purity as low as 10% and be highly adulterated with other non-controlled drugs. 

Cannabis production and cultivation

Even long established processes like the domestic indoor cultivation of cannabis, using small and often rather amateurish set-ups, have been superseded by organised crime groups, who have turned cannabis cultivation into a uniform, highly organised, commercial process, involving cannabis factories at multiple locations generating very substantial profits, which are often linked to associated crimes such as money laundering. Although the small domestic growers still remain, in the current drugs climate, their efforts to establish their own domestic supply of cannabis may often be misinterpreted as commercial cultivation.

The requirement for a drugs of abuse expert

Therefore, when selecting a forensic defence expert to comment on the evidence presented by the prosecution it is crucial to choose one who has current detailed knowledge both of today’s drugs markets and production processes, but also (given the length of time that some cases take to go through the legal process) has knowledge of historical drugs markets and productions too.


Forensic Equity’s drugs experts are all currently actively working in the field of forensic drugs for both the prosecution and the defence and are therefore uniquely placed to provide the best possible expert witness reports for your clients.

Cannabis Production and Cultivation 

Drug Legislation 

Criminal cases involving the possession, sale, manufacture and importation of drugs in the UK are governed by two main pieces of drug legislation:

  1. The Misuse of Drugs Act 1971 together with all its subsequent amendment orders.

  2. The Medicines Act 1968 which defines three legal categories of medicines.

Details of the Misuse of Drugs Act 1971

This act divides controlled drugs into three classes A, B and C ostensibly, on the basis of perceived harm. Class A drugs are perceived as the most harmful and are therefore linked to the most punitive penalties. Class C drugs are perceived as being the least harmful and are therefore linked to the least severe penalties. A full list of Illegal substances and the sentences they carry can be found here.


Information on amendment orders

In recent years many new drugs have been added and continue to be added to the Misuse of Drugs Act 1971 in the form of amendment orders. Drugs that were so called ‘legal highs’ (i.e. which were abused recreationally, but could legally be bought and used in the UK) can be quickly added to the Act by means of the Home Secretary invoking a temporary class drug order. This order comes into effect immediately after parliament has agreed it and lasts for up to 12 months. 


However, this ability to amend effectively obviates the need for having to prove a particular drug is harmful.  In theory if a drug is added temporarily and is later proved not to be harmful it could be removed from control, although in practice this is unlikely to happen.


Drug possession charges - Example defence issues

It is therefore possible that someone could have purchased drugs when they were not controlled. But then subsequently have them seized by police after they have become controlled and would therefore be charged under the Misuse of Drugs Act. 


Because there are many variants of drugs, they are controlled on mass, based on their chemical structure, rather than by naming them specifically. This can make ascertaining whether certain new drugs are controlled or not quite difficult unless, one is a forensic drugs expert with the ability to undertake independent drugs comparisons and purity analysis.


Details of the Medicines Act 1968 and the three legal categories of medicines.

  • General sales list medicines (GSL)

These require no prescription and may be sold in a wide range of shops. They would include things like low strength paracetamol tablets, cold medicines, vitamins and herbal remedies.

  • Pharmacy medicines (P)

These may only be sold in pharmacies and a pharmacist must make or supervise the sale. They would include things like nasal decongestants and antihistamines.  In addition, some pharmacy medicines may only be sold if the pharmacist is satisfied that the person buying the medicine meets certain medical criteria.

  • Prescription only medicines (POM)

These medicines may only be obtained from a pharmacist upon presentation of a prescription from a GP, dentist or other registered healthcare professional. It may be possible to obtain some prescription medicines for personal use via the internet from overseas, but anybody who is not a registered healthcare professional who then seeks to sell them onto others, will be contravening the Medicines Act 1968 and can be prosecuted on that basis.


Some Prescription only medicines (POM) are also controlled under the Misuse of Drugs Act (MDA) 1971 (as amended). This means that it is a criminal offence to possess them without a valid personal prescription and it is a criminal offence to sell them to others. These would include preparations like Valium, which contains the drug diazepam, which is a Class C controlled drug under MDA 1971 (as amended).

How can our drugs expert help?

  • Our drug experts have an extensive understanding of the Misuse of Drugs Act 1971 and regularly update their knowledge as to which drugs have been added to the the Act and when. As such they can provide expert evidence on all related issues. As an example, they can provide expert witness testimony to confirm whether a drug could have been bought legitimately and was then subsequently controlled.

  • Our drug experts are also suitably qualified to be able to determine whether or not a drug is actually controlled by means of its chemical structure. If required we also have the capability to conduct drug testing and analysis in order to independently determine its chemical composition, purity and thus its correct classification.

  • Our drug experts are also fully conversant with the Medicines Act 1968 and can provide expert opinion on whether certain drugs or chemicals can be legitimately sold by non-registered individuals.


Drug Testing and Analysis 

On some occasions in criminal drugs cases the original drug testing and analysis by the prosecution scientist is called into question or was not comprehensive enough. These issues can be addressed and the defence aided by instructing an independent forensic scientist to re-examine the drugs and the analytical results in question.


Increasingly, it may also be necessary for our forensic scientists to carry out fresh testing and drug analysis or extend the scope of the original analysis at ones own independent forensic laboratory.

Drug testing and analysis - use in civil cases

Drug testing and analysis can also be an issue in civil cases, particularly where the custody of children cared for by parent/s who are drug users are concerned. It may be in the interests of child safety to ascertain the identity of suspected drug substances found within the home using our forensic drug testing and analysis services.


Independent forensic analysis at our laboratory facilities

Forensic Equity has access to the most up to date forensic laboratory facilities for drug testing and the analysis of controlled drugs. This facility also has secure storage to ensure the safe deposit of any samples sent to us for analysis. Importantly, we also have the forensic scientists with years of experience in forensic analysis who can properly analyse the samples, interpret the results and provide expert witness reports tailored to your requirements and the issues that you need addressed.


Drug Valuation 

Drug valuation is key in cases of asset seizure under the proceeds of crime act (POCA). The valuation of the drugs in each case has become a very important and often very punitive part of the sentencing procedure in drugs cases involving the importation, production and or supply of controlled drugs.


Apart from the seizure of any available assets, any assets deemed by the Crown as ‘hidden assets’ resulting from such activities can lead to years being added onto any custodial sentence already imposed. It is therefore crucial in such cases that the amounts of any drugs involved and the value of any alleged profits are carefully assessed and put into context by an independent drug expert witness.

Our forensic scientists have years of experience and unrivalled expertise in the field of controlled drugs and drug valuations. What is often not appreciated by the layman is that different forms of the same drug will command different prices in the UK drugs market and such prices will be dictated by supply and demand for a particular drug or for the form of a particular drug. They may also vary from area to area within the UK and from year to year. 


Drug valuation case example

Person convicted of importing drugs into the UK and selling them on was given a custodial sentence. The Proceds of Crime Act was invoked to seize assets allegedly gained from the illegal drug activity. In addition the Crown also alleged the existence of hidden assets.


The assets of the accused which related to drug dealing were allegedly several million pounds - A figure which was extrapolated from the drugs valuation provided by the Crowns drug exert.


However the amount of drugs,  types of drug and therefore the value of the drugs involved were all disputed by the defence


How can our drug expert witness assist the defence case?

Our independent expert could, by forensically examining the ‘dealers’ own  records,  ascertain that  lower amounts of different types of drugs had been imported and sold. In doing so our expert could provide a more balanced valuation of the drugs in question and thus substantially reduce the value of the assets under threat of seizure.


Our drug expert witness can:

  • Check the amounts of drugs allegedly sold from ‘dealer’ records

  • Establish what form the drugs were in

  • Comment on the original Crown valuation

  • Re-value the drugs based on information supplied by the defence.

  • Examine detailed information from the  defendant, including one to one discussions in the presence of their solicitor, if appropriate.

  • Write an expert witness report to present the re-assessed drugs values

  • Attend court to give expert evidence as appropriate and assist in cross-examination as required.


Drugs Comparison and Purity Analysis

Drugs Comparison and Purity Analysis

Illicit drug powders normally contain a number of components, which will include the principal illicit drug (e.g. cocaine) and impurities related to that drug. They may also contain other drugs as adulterants and may also be diluted ('cut') with other commonplace substances (e.g. sugars). Drug powder comparisons are usually based on appearance and detailed chemical composition (which may be more or less characteristic depending on the mix of components) and are often used as evidence of drug dealing. For example if the composition of an illicit drug preparation found on one person matches that found on another person, with whom they are known to have had recent contact, then the inference is that one person could have supplied the other with those drugs.

Drug comparisons case example

Person found in possession of a bag of powder suspected to contain a controlled drug. A known associate of theirs is found in possession of two small wraps of what is suspected to be the same controlled drugs powder. The powders are forensically analysed and found to have similar chemical compositions. The person who possessed the bag of powder is charged with possession of a controlled drug with intent to supply. The other person is charged with possession of a controlled drug. Police may also apply for forfeiture of the suspected dealers assets under The Proceeds of Crime Act 2002 (POCA).


How can we help?

Our forensic scientists have years of experience carrying out comparisons on illicit drug preparations and interpreting the results. They also have up to date knowledge of how commonplace or otherwise those preparations might be, based on their chemical compositions.


Our forensic scientists can:

  • Peer review the original forensic comparison of the drug samples in question and the interpretation of the results.

  • Carry out further examinations if appropriate

  • Evaluate the strength of the forensic evidential link between those drugs samples, based on the commonality or otherwise of their chemical compositions.

  • Evaluate the forensic findings in relation to the circumstances which surrounded the seizure of the drugs.


Drugs on Money

Under The Proceeds of Crime Act (POCA) both the Police and Her Majesty's Revenue and Customs (HMRC) are permitted to confiscate money and seize banknotes, if it can be shown to be associated with drug dealing or drug trafficking. One way of doing that is to analyse seized bank notes for traces of controlled drugs (so called drugs on money). However, if traces of drugs are detected on those banknotes the big question is how did those drugs get there?

Banknotes contaminated with illicit drugs - Asset seizure and confiscation under the proceeds of crime act 2002 money laundering 


Recent statistics indicate that in London alone 99% of all banknotes in circulation may be contaminated with cocaine. The prevalence of general circulation banknotes contaminated with other controlled drugs will vary depending on the drug. However, indications suggest that contamination of general circulation banknotes with other common drugs may also be rising. This raises the question of how different is the drug contamination on the seized cash to the drug contamination on banknotes in general circulation.


Our scientists are experts in drugs contamination on banknotes and can reanalyse the evidence from banknotes seized under the proceeds of crime act and put any drugs contamination found into context. 


Confiscation and seizure of modest amounts of money


It is not common knowledge that in civil cases, where the police seek to confiscate relatively modest amounts of money and cash under The Proceeds of Crime Act (POCA), that they believe to be drugs related, that those banknotes may not be subjected to  detailed forensic drugs testing  (i.e. A full Mass Spectrometry analysis by a recognised forensic provider).  Instead police officers may choose to subject some of the banknotes seized to presumptive in-house testing, using a screening device known as an ‘Itemiser’. This presumptive testing may then be used to apply to the court to confiscate all of the cash, based on the premise that the owner of the money is not likely to contest its confiscation. This form of presumptive testing is open to question and different interpretation if reviewed by a forensic expert in drugs on money testing. Our experts have unrivaled knowledge of this Itemiser testing process and interpretation of the results that it generates.


Drugs on money - case example


A person found in possession of a large amount of cash, which the police suspect is the proceeds of drug dealing. The banknotes are analysed for traces of controlled drugs and the presence and contamination of heroin is reported. The owner of the money is charged with drug offenses and and the police apply for forfeiture of the cash under The Proceeds of Crime Act 2002 Money Laundering.


How can our forensic scientists whom are highly skilled in the analysis of drugs on banknotes help?


Our forensic scientists have years of experience in trace analysis and in reviewing these types of cases. They can re-evaluate the forensic evidence to include:

  • Analysing samples of the seized cash and banknotes to re-determine the levels of drugs contamination

  • Address potential contamination issues related to the circumstances under which the cash was seized and the subsequent examination and analysis of the drugs found on the banknotes by police officers or forensic scientists.

  • Put the level and extent of the drugs contamination found on the money into context and explain what the analytical results actually mean in a wider context having considered a wider data set.

  • Consider the analytical results in relation to any legitimate reasons why those bank notes became contaminated with drugs.

  • Answering any other questions posed by the defence counsel in relation to the drugs contamination on the cash.

  • Appearing as an expert witness for the defence, parting current credible knowledge and forensic interpretation capable of withstanding even the toughest scrutiny from the prosecution and during cross examination.


Drugs Packaging Comparison

Plastic packaging materials (e.g. bags and cling film) are commonly used to wrap quantities of illicit drugs, for storage or to sell as 'deals'. When those plastic packaging materials are produced the manufacturing process will leave 'marks' on that packaging, which may be characteristic of a particular piece of manufacturing equipment and a particular time period in one manufacturing run, on that equipment. Those manufacturing 'marks', along with other physical and chemical characteristics of the packaging material can be used to compare samples of packaging and possibly link them evidentially to a common source.

Drugs packaging forensic comparison - Case example

Police officers find a number of plastic bags filled with powder (suspected to be heroin) hidden in a container in a garden, close to the home address of someone they suspect is the owner of those drugs and a suspected dealer. They search the home address of that person and find no drugs, just a part- used roll of similar, but ordinary, freezer bags. The bags of powder and the roll of bags are sent for forensic examination. The powder is identified as heroin with a total weight of 1 kilogram. The plastic bags used to wrap the powder and the bags on the roll are compared and found to be similar. The forensic report indicates that the bags used to wrap the heroin and the bags on the roll are linked evidentially. The owner of the roll of bags is charged with possession of a controlled drug with intent to supply. The police may also apply for forfeiture of assets under The Procceds of Crime Act 2002 (POCA).


How can we help in the defence?

Our experts have many years of experience of examining and comparing all types of packaging materials and assessing the evidential significance of their findings.


Our forensic scientists can:

  • Peer review the original forensic examination of the packaging and the conclusions drawn from it.

  • Re-examine the packaging if appropriate.

  • Evaluate the strength of the forensic evidence of a link, based on the commonality or otherwise of the packaging material involved and the nature of the manufacturing marks found on it.

  • Evaluate the forensic findings in relation to the circumstances surrounding the seizure of the packages of drugs and the roll of bags.


Drug Trace Detection and Detection Devices 

Police officers use portable trace detection devices for a number of purposes, including screening seized banknotes or licensed premises for traces of controlled drugs. If those premises test positive for drug traces, the police could apply to have the landlord's license to sell alcohol revoked, on the grounds that they allowed those premises to be used for consumption of controlled drugs.

Drugs trace detection and detection devices - Case example

A public house where the police suspect the customers are habitually consuming controlled drugs is visited by police officers and areas within the premises are swabbed. Those swabs are screened for the presence of controlled drugs, using mobile drugs detection devices. The testing indicates that some of the areas tested within the premises are contaminated with traces of cocaine. The police use those results to apply for the alcohol license for the public house to be revoked.


How can our forensic scientists help?

Trace detection is an area of forensic drugs analysis which has to be carried out under stringent conditions as the tester is effectively analysing for invisible traces of drugs and inadvertent contamination of items is a real possibility. Our experts have years of experience of trace analysis and are well versed in the strict protocols that need to be followed to minimise or rule out the risk of inadvertent contamination during the testing process.


Our forensic scientists can:

  • Review the testing protocols and test results to determine if they meet the required standards for trace detection.

  • Address any limitations of the testing equipment used, in relation to the type of testing it was used for.

  • Address any potential contamination issues relating to the testing of the premises.

  • Put the level and extent of drug contamination found within the premises into perspective, by explaining what the results really mean.

  • Evaluate the test results in the context of the circumstances surrounding the case.



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