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Dr Samantha Stewart

Forensic Toxicology Reporting Officer, Randox Testing Services.

Studied Chemistry at Queen's.

two female students in labcoats using a pipette dropper to add a substance to a test tube

Who do you work for?

I work for Randox Testing Services. We provide drug testing for companies in industries including aviation, maritime, transport and also for local authorities. We also provide forensic toxicology testing and expert witnesses for half the police forces in England and Wales. This involves testing bodily fluids for example blood, urine, hair, stomach contents and vitreous humour for the presence of both illicit drugs and prescription medications. We handle a variety of cases ranging from road traffic cases, drug-facilitated sexual assaults, murders and post-mortem cases, where a pathologist will want to know if any drugs present in the deceased have caused death.


What is your role and what does this entail?

Currently, I am a forensic toxicology reporting officer. When a case comes into the laboratory, I assess the case history provided to me and it is my duty to determine both the best testing profile and on which sample to conduct the work on.

Once all testing is complete, I gather the results of the different tests carried out. Once these are compiled I will write an expert witness statement summarising the findings and then using my expertise to interpret the results. Depending on the type of case I am usually asked to comment on the effect of the presence of any drugs found on the person the samples were taken from. For example, in road traffic cases this will usually entail describing typical symptoms of any drugs found and how this may affect a person’s ability to drive safely.

My involvement in the case does not necessarily end upon completion of the witness statement. If the case goes to court, my statement is entered as evidence for that trial. If the prosecutor feels my presence at court might help explain my findings to the jury, then I will be called to court to give evidence. If the defense does not agree with my evidence, then they may also call me to court and I can be cross-examined on my statement.


Outline your career to date

I began with Randox Testing Services after completion of my PhD. My initial role was to develop assays for testing of blood and urine for drugs of abuse. This involved method development, validation and accreditation to ISO 17025 standards.

I had a natural interest in taking the numbers (concentrations) measured by my tests as what this may mean in relation to effects on an individual. As such I began training to become a reporting officer. Initially this meant learning about the different types of drugs and the typical effects they may cause on an individual. I began with road traffic cases which typically entail the illicit drugs of abuse (e.g. cocaine, cannabis, amphetamines) and as I gained more experience I moved to the more complex case types. Before becoming a reporting officer I had to undergo court room training, where a barrister would provide training on the legal system and my responsibilities as an expert witness. I was also trained on providing testimony in court and undergoing cross-examination in the witness box.


Tell us about your qualifications/training

I hold a master of science degree (MSci) and a PhD, both of which were awarded by the School of Chemistry and Chemical Engineering at QUB. I am also trained to give evidence in court.


Did you always want to work in your chosen sector?

Yes. I have always enjoyed science and the idea of using science to link a suspect to a crime scene always interested me. One of the most common questions I get asked is “You’re a forensic scientist, like in CSI?” The answer is no! While some of the content is based upon real principles and techniques, the programme sometimes exaggerates the capabilities of these instruments and techniques. In reality forensic science can play an important part in solving a crime and toxicology in particular can give insight to a person’s state of mind during a period of interest but it isn’t the only piece of the puzzle.

What qualities are required for your position - personal and professional?

One important quality is to be meticulous in your approach to your work. The forensic science industry is heavily regulated. We have many procedures to cover each stage of the analytical process for samples undergoing testing. Each member of the team throughout the process adheres to these procedures. This ensures that all work conducted is done with the highest quality standards, this is important for me who goes to court to stand-by these findings. If the defence can demonstrate that procedures were not followed then this can be a reason for my evidence to be thrown out- so it is incredibly important to be thorough in my work and instil the same high standards to all team members.

Communication is very important too as I have to devise strategies for cases coming into the laboratory and ensuring that each person in the team knows what the case requires. Attending court means that I have to be able to communicate scientific findings to laymen (juries, prosecutors, police officers) who do not have a scientific background. So the ability to simplify the results is very beneficial.


What do you do, day-to-day?

In the laboratory, no two days are the same. It really depends on what the priority is for that day. New cases come in every day, so time is required to assess them and devise an appropriate strategy. This may also include liaising with the police officer in charge to determine what exactly is required for the case.

When it comes to writing reports there are different varieties of reports to be written and that will also change day-to-day. Apart from the different types of cases (road traffic/ drug-facilitated sexual assault/ post-mortem), the complexities of each case may vary. For example, there could be several types of drugs present and the interaction of all drugs with each other must be considered.

If I have an upcoming court date, I must also take some time to prepare my travel arrangements and refresh myself of the case. It can typically take 6-12 months from completion of my statement, to a case going to trial. So there is plenty of variety for a forensic scientist.


Detail any recent projects that are reflective of your job and your industry.

Unfortunately due to the nature of my work, I cannot talk about specific cases. However, for a typical road traffic case, I will be provided with a blood sample and asked to test it for alcohol and common drugs of abuse (typically cocaine, cannabinoids, benzodiazepines, opiates, amphetamines and ketamine). For cases involving alcohol only, it is straight-forward. This is because the government has set legal limits and so the person is either above or below this limit. With drugs, currently there are no legal limits so it is not as clear cut as for alcohol cases. There are proposals for legal limits for the most common drugs but these are not in place yet. Therefore, a case is built on whether there was a significant quantity of drug(s) present to exert an effect on the individual. Did the individual display symptoms consistent with intoxication of this drug? Quite often a case will rely on the toxicology findings and the observations of the forensic medical examiner who collected the sample and the subject’s driving manner which caused the police officer to pull the individual over.

I may also be asked to comment upon negative findings, that is I have tested the sample for the presence of a drug and the result was negative. This is more common in alleged drug-facilitated sexual assault cases where a victim may have unwittingly had their drink spiked with a drug capable of rendering them unconscious. Some of the drugs used in these cases are long acting and can be detected in the urine sample of a victim up to four to five days after the incident. However, some drugs may be undetectable within 12 hours and in some cases the assault has not been reported within this period. As such, the negative findings do not exclude use of the drug.


What makes working in your industry interesting and challenging?

The field of forensic toxicology offers a wide range of professional specialisms and areas of expertise that an individual can choose to pursue. For example, some toxicologists may specialise in road traffic cases or post-mortem cases or the interpretation of hair toxicology results.

I’ve personally had the opportunity to work alongside a broad variety of individuals from different scientific backgrounds. I’ve had the chance to learn and gain knowledge and experience from outside my own academic specialism. Due to this working environment, there is often the opportunity to learn new skills and stepping into new roles as and when required. I also enjoy the ability to work with other members of the criminal justice system such as police officers, lawyers, judges and pathologists.

There is always an opportunity to learn something new and to build experience when working with continuously challenging and unique cases.  Because cases vary greatly from one to the next, each case is dealt with on its own merits based on its complexity and the unique information provided. This helps create an interesting, challenging and proactive working environment to meet deadlines and provide my expert opinion on cases and prosecutions, whose outcomes depend greatly upon the accuracy and proficiency of our work.


What career progression opportunities are available?

I was lucky and began my career with Randox Testing Services when the customer base was smaller than it is now. As such, I have been able to develop with the business and take on additional responsibilities as the company required. Now that I am more focused on the reporting side of the business, I can go on to become a Senior Toxicologist and decide to specialise in a particular case-type. I particularly enjoy the more complex cases where the combination of a large number of drugs may make interpretation less straightforward.


What kind of personality do you need to operate within your chosen industry?

I am involved in a wide variety of cases and for some of these, the case history may involve up-setting circumstances. So being able to maintain professionalism and to treat the case objectively when the circumstances are hard to remain detached from is important.

In my experience, this industry requires the ability to work collaboratively with a broad range of people, often within scientific and layman professions. The ability to adapt methods of communication to a variety of audiences is essential. For instance when being cross-examined, you can never predict the type of question you may be asked by a barrister with little-to-no scientific background. Therefore, the ability to think on your feet, while conveying my answer in a way that a jury is still able to understand is incredibly important.