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Strands of Evidence

For many years now, hair testing has been used as a useful tool within the legal/medico sector to provide crucial evidence of exposure or use and of substances including prescription, over the counter and illegal drugs, but are you making full use of this clever technology? Are you using the right methods and types of analysis? Do you know what is available and how it can help your specific case? What is “Chain of Custody”? Is it legally defensible? Where can I get the best free advice from? What else could I use this technique for?



Hair Testing

Hair testing is unique in its ability to look back months rather than days at drug and/or substance use, making it an essential piece of the jigsaw in child residence, protection orders, family and criminal cases. By providing information on exposure over time, hair analysis can be useful in verifying self-reported histories of use in any situation in which a past history use is desired. During controlled tests of hair, a drug/substance user is not able to hide the fact that they have used drugs. Once ingested, the drug remains in the hair as a permanent record. Drugs in the bloodstream get trapped in the hair shaft as it grows in the root follicle. Since hair is an inert protein, the drugs remain trapped there until the hair is cut. After about 7 days following drug use or exposure, the hair has grown enough to be cropped close to the scalp, providing the perfect history of drug or substance abuse/exposure. On average, hair grows at about 1cm per month, so a 3 cm section gives a three month history of drug use. If more in-depth detail is required, the hair can be sectioned into, say, 3 x 1cm to show what has been taken month by month. Similarly this can be done for as long back as the subject’s hair measures.

Choosing the correct type of analysis

The result of any hair test is an average over the time period tested for. If a subject who had consumed a drug in excess of the cut-off (for example 50pg/mg) for say two months, but was abstinent for the next four months, it may be reported back as a NEGATIVE (i.e. <50pg/mg) when averaged out over the six-month period i.e. where a 1 x 6 cm sample was analysed. In order to obtain a clearer more detailed picture of the levels of the consumption of the drug over time, a head hair test should be employed and split into segments or sections.
For example:

A person drinks in excess of 6.25 units of alcohol per day each day over the period of July giving a result in hair for Ethylglucuronide (Alcohol) for the month of July of 52pg/mg. In August and September, the person did not drink any alcohol. 50pg/mg is assumed as the cut-off level for a positive/negative result.

A 1 x 3cm hair analysis would show NEGATIVE for Ethylglucuronide on average over the 3 months (i.e. 52pg/mg divided by 3 months = <50pg/mg).
However…

A 3 x 1cm hair analysis would show POSITIVE for Ethylglucuronide on average over the month of July, and NEGATIVE on average for the month’s of August and September.
As demonstrated in this example, the same 3cm sample can be shown as a positive or negative result dependent on the type of analysis used.

Therefore, with segmental analysis, more accurate patterns of use can be obtained and observed. The same principle can be applied to any drug or substance. This method is particularly important when a subject is claiming to have been “spiked” (administered a drug or substance without their knowledge) or where a one off use is declared or assumed.

The process of hair testing has been proven in a court of law many times and therefore has grown in popularity because it provides a complete history of substance, drug (and now alcohol) abuse or exposure. Often a donor will attend the interview having just shaved his head as a way to avoid detection. However, under-arm, body (chest, leg etc) or pubic hair can be utilised, with each offering a different “window of detection” (how long back you can look at). One UK provider can even use nail clippings where no hair at all is present.



Choosing a provider

When choosing a provider, you should ask yourself a number of questions, including:

• Quality – Do they meet the required UK, European and Worldwide standards? Do they have World leading experts in the team? Do they deliver the most accurate results available to me/the client/the court or are we settling for “second best”?

• Reliability – Do they deliver what they promise and will I get my results in time? Can I trust them to “get on with the job” while I get on with mine?

• “Chain of Custody” – Do they offer a flexible (to meet my/my clients’ diary) fully competent and trained collection service to meet legally defensible Chain of Custody? Do they have robust procedures to ensure this?

• Choice – Can they provide the widest range of analyses to meet your/your client/the court’s specific needs? Do they advise what is available and can they offer choice?

• Ability - Can they test for the widest range of substances and not just the “standard panel”? E.g. Most providers state that they test for Benzodiazepines, but they will only test for a small few (the easier ones to detect) and therefore will miss crucial evidence. Do you need to look at ALL of a specific drug type, not just a limited section of that drug type?

• Accuracy – Can they deliver highly accurate and reliable results that will stand up to external scrutiny or challenge? Do they use the latest technology and methods? Do they “lead” or do they “follow”?

• Sensitivity – Are the analyses sensitive enough to detect drug or substance use or exposure at ALL levels and not just at the medium-higher levels? E.g. Cannabis is difficult to detect at low levels, most providers will not inform you of this because they cannot offer a “low” level cannabis test. Will you miss that crucial evidence?

• Customer service – Are they friendly, professional and how quickly will they respond? Will invoices be sent on time and will they be correct? Are you kept informed of any changes that may happen along the way? Are they available 24 hours a day, 365 days per year? Would you recommend them to peers?

• Advice and Support - Can I discuss what best suits the case and get ongoing confidential free expert advice throughout the whole process? Can I get Expert Witness from a world-leading expert? Does their report hold substance when challenged? Are they experienced in high profile cases or will their evidence (written or in person) be dependable in court?

• Cost – What am I/the client/the court getting for the money? Is it good use of public or the client’s funds? Will I get the specific evidence I need or will it be ambiguous and therefore open to challenge? If it is done incorrectly or insufficiently the first time, then it may need to be done again.

 

 

It Sample Collection and Chain of Custody

It is recommended that persons involved in commissioning a hair test appoint an independent sampler to collect and verify samples, as it is the best way to ensure Chain of Custody (the strict systems and processes required to guarantee the authenticity of the sample and it’s analysis). The donor is required to give a hair sample with their consent. This would require a sample of hair to be cut from the crown of the head, called the vertex posterior. Compared with other areas of the head, this area has less variability in the hair growth rate - the number of hairs in the growing phase is more constant. Underarm, chest or leg hair is also an option if no head hair is available. An A and B sample can be collected if required with the B sample being stored securely for a minimum of 12 months. A sample of approximately 150 hairs (the width of a pen barrel) is required for an average test. It should be noted that accuracy of hair analysis is reliant on the weight of the sample. Some companies state that they only need to take a tiny amount of sample. This is one area where their results are left open to challenge. The sample is then placed into a special envelope, signed by the subject and sealed by the “Collection Officer” in front of the subject. This is then put into a larger envelope and sealed to complete the Chain of Custody. The form is signed and completed and sent to the laboratory with the sample.


Laboratory processes

The samples are checked at the laboratory to ensure tamper proof seals are not broken and then follow an approved and accredited (via audit) process through the laboratory. The hair analysis involves many processes but below are the main 5 steps:

• Decontamination of the hair

• Preparation of the hair: pulverization, segmentation in short pieces

• Incubation: in methanol, acid, sodium hydroxide, buffer

• Extraction: liquid/liquid, solid phase, solid phase micro-extraction

• Analysis: Chromatography (GLC, HPLC) coupled to mass spectrometry or tandem mass spectrometry.

This process including the issuing of results and expert witness statement usually takes on average about 7-10 working days.

In Conclusion

Hair testing offers a unique window of detection for substances, drugs and alcohol. It provides a way for you to look back months rather than days (in the case of blood or urine) to ‘rule in’ or ‘rule out’ drug and alcohol use or exposure to a substance in a specific case. When used correctly, it can be a powerful tool to demonstrate patterns of use or exposure allowing professionals to make informed decisions to build and support their case adding clarity to allegations or even assumptions. It can give confidence to professionals to make the right decisions at the right time.

There are many applications for this modern technique in all aspects of law. Its application should be considered in length and how the different techniques can be applied to provide a far more detailed history of use, abuse or exposure than often thought or assumed. It is proven, reliable, accurate and cost-effective - but only when done in the correct manner. It is important to get the right advice and employ the services of the right experts.

When you get the best information, it allows you to make the best decisions. It could be the difference between placing children in a harmful environment or one of safety and wellbeing. It may be the crucial part of evidence that can win or lose your case. It could prove or disprove that someone was indeed “drugged” over time (long or short). Whatever the application, you can guarantee that hair testing techniques will continue to improve the availability of reliable evidence, much as DNA has in recent times.

Author: Matt Taylor, Managing Director of ScreenSafe UK (World leaders in Hair Testing services).matt.taylor@screensafeuk.co.uk
www.screensafeuk.co.uk
Tel: 08450 50 55 90

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