A study of blood and urine alcohol concentrations in cases of alleged drug-facilitated sexual assault in the United Kingdom over a 3-year period

This paper details the alcohol concentrations found in a selection of 1014 cases of claimed drug-facilitated sexual assault analysed at The Forensic Science Service, London Laboratory between January 2000 and December 2002. Where appropriate, either a whole blood sample and/or a urine sample was analysed for alcohol, common drugs of abuse and potentially stupefying drugs.

The samples were collected from a complainant within 12 h of an alleged incident in 391 of the 1014 cases analysed. Of these, the majority (81%) contained alcohol. The presence of alcohol itself was not surprising as most of the alleged incidents were associated with social situations such as at a public house, bar, night-club or party, where it is expected that alcohol would have been consumed. However, 233 (60%) of the 391 cases had a high back-calculated figure, where high is defined as greater than 150 milligrams per 100 millilitres (150 mg%). Some of these samples were also found to contain illicit drugs. This is the first paper to our knowledge which discusses in detail the significance of the alcohol concentrations found in cases of this type.