Drug field tests are rapid screening tools used to identify suspected illicit substances on-site. While these tests are quick and convenient, they are prone to false positives due to their limited specificity and susceptibility to cross-reactivity with legal substances. As such, their results should be treated as preliminary and not conclusive. Challenging field test results is crucial in ensuring accurate outcomes in drug-related cases, often requiring confirmatory testing through advanced laboratory techniques like Gas Chromatography Mass Spectrometry (GCMS) to provide definitive identification.
At Bericon, we specialise in providing expert forensic services to challenge the reliability of drug field tests.
Case Study – Key Information:
– The defendant was charged with the Possession of a Controlled Class A drug, namely cocaine.
– The defendant was found in the possession of plastic wrap containing a white powder.
– The sample was tested by the police using a so-called field test and said to contain cocaine.
– The defendant disputes that the above test and states that the sample contained vitamin C and a drug called pregabalin.
Expert Instruction:
Bericon’s expert was requested to undertake a laboratory analysis of the above powder and determine whether it did contain cocaine.
Expert Findings:
A field test can only ever be an indication of what a sample contains and confirmatory testing by advanced instrumentation is required for conclusive identification.
Bericon’s expert collected a sample of the powder and it was submitted for independent testing using a technique called Gas Chromatography Mass Spectrometry (GCMS).
This confirmed that it did not contain cocaine. Therefore, the police result must have been a false positive.
Are you a criminal defence solicitor looking for an expert witness in this type of case? Contact us today.
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