SOFT 2004 Meeting Abstracts - Society of Forensic Toxicologists

B8
TOXICOLOGICAL FINDINGS IN CASES OF ALLEGED DRUG FACILITATED SEXUAL
ASSAULT IN THE UNITED KINGDOM
Michael Scott-Ham BSc and Fiona C. Burton PhD*: The Forensic Science Service, London Laboratory,
109 Lambeth Road, London, SEI 7LP, UK.
The Forensic Science Service (FSS) is the major provider of forensic services in the UK. It has several
laboratories throughout the country with two providing forensic toxicology services. These two
laboratories annually deal with approximately 500 cases of alleged drug facilitated sexual assault (DFSA)
submitted from various UK police forces.
This study outlines the results from 1014 cases of claimed drug facilitated sexual assault analysed at the
Forensic Science Service, London Laboratory between January 2000 and December 2002. As and where
appropriate, either a whole blood sample or a urine sample from the complainant was initially analysed for
alcohol and common drugs of abuse. The test for alcohol was by gas chromatography and for common
drugs of abuse by immunoassay with positive results being confirmed by gas chromatography-mass
spectroscopy (GC-MS). Common drugs of abuse tested for include cannabis, amphetamine, Ecstasy,
cocaine, opiate drugs, methadone, barbiturates and the benzodiazepine drugs diazepam and temazepam. All
urine samples (or blood sample if urine not collected) were further tested for potentially stupefYing drugs
and their metabolites by either positive or negative ion GC-MS (as applicable). These tests have been
shown to have the low limits of detection required to detect the drugs of concern. Potentially stupefYing
drugs included a range of other benzodiazepine drugs (including flunitrazepam) and related drugs such as
zopiclone, gammahydroxybutyrate (GHB) and a range of chemically basic pharmaceutical drugs such as
ketamine and other medicinal drugs with sedative properties. The urine samples were also tested for
trichlorinated compounds (e.g. chloral hydrate) by a colour test.
The results are interpreted with respect to the numbers of each drug detected. An attempt has been made to
distinguish between voluntary use and involuntary ingestion by using information provided by the
investigating police officer (with follow-up discussion where necessary). Furthermore, in those cases
where alcohol was detected, the most likely blood alcohol level at the time of the alleged incident has been
calculated.
Alcohol (either alone or with an illicit or medicinal drug) was detected in 46% of all cases and in 81 % of
the cases in which the samples were taken within 12 hours of the alleged incident. Of the cases where
alcohol was detected, 60% had a high back-calculated figure. For the purposes ofthis paper high is defined
as greater than 150 milligrams per 100 millilitres (%). Illicit drugs were detected in 34% of the 1014 cases
with cannabis being the most commonly detected drug followed by cocaine, benzodiazepine drugs, opiate
drugs, Ecstasy, amphetamine and methadone. A number of samples contained more than one illicit drug.
In 2% of cases, a potentially stupefying drug was detected which had not been admitted and therefore could
be a genuine DFSA case. GHB was detected in some of these cases but neither flunitrazepam nor its
metabolites was detected. Although sedative drugs were detected in many more cases, complainants
admitted prescribed use of these medications. A wide range of non-sedative pharmaceutical drugs were
also detected. The types and numbers of all these drugs will be presented (together with examples of
typical limits of detection).
The results of these studies are in agreement with other studies published in this area. However, this is the
first study to our knowledge which has attempted to identifY the 'genuine' cases and which discusses in
detail the significance of the alcohol levels found in cases of this type.
Keywords: DFSA, flunitrazepam, alcohol
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