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Inconsistent Consent

Written by: Alan Baker 3rd February, 2023


The significance of alcohol in a complainant’s blood sample is a frequent consideration in cases of sexual assault.

Studies in the US have shown that this type of case is more likely to be dropped prior to trial and are less likely to be investigated or prosecuted when the victim used alcohol or drugs.

In many US jurisdictions, intoxicated victims may be considered mentally incapacitated only if they have been administrated alcohol or other substances involuntarily.

Thankfully this is not the case in the UK, but problems do persist in relation to the effect of a given blood alcohol concentration and the likelihood (or not) that an individual could or could not consent to sexual activity.

The best that forensic scientists can offer is to typically present a range of effects for different blood alcohol concentrations, e.g.

100 – 150mg% – Impaired balance, thickened speech, clumsiness, reduced alertness, lowered social reserve.

150 – 200mg% – Drunkenness, slurred speech, glazed eyes, flushed complexion, staggered gait, drowsiness, exaggerated emotional responses, impaired co-ordination, reduced inhibitions, dizziness, nausea, disorientation.

200 – 250mg% – Marked or heavy drunkenness, confusion, grossly impaired co-ordination, vomiting, reduced awareness, short-term memory may be impaired.

In a case where alcohol consumption and effects are major features, the single biggest overlap of effects and therefore contention relates to that of euphoria and loss of inhibition versus impaired consciousness. These considerations are often critical in a case where sexual assault has been suggested.

Although there is extensive research on the links between alcohol and alleged sexual assault, there is still a lack of clarity about the exact role that alcohol could play in facilitating any incident.