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The chain of evidence is a legal concept, which requires that the origin and history of any exhibit to be presented as evidence in a court of law must be clearly demonstrated to have followed an unbroken chain from its source to the court. All persons handling the sample and the places and conditions of storage must be documented, with a note of the time, date and place and signatures where appropriate.
When sending a toxicology specimen in any case where there are child protection concerns, a laboratory chain of evidence form (LCOEF) should be completed by the doctor sending the sample. It should be stapled to the HISS request form prior to sending the toxicology sample to the laboratory. A second person will need to sign that they witnessed the sample being collected/sent (this should be a member of staff who was involved in the collection of the sample). If several samples for toxicology are being collected then a separate form needs to be completed for each sample. The laboratory should also be notified by telephone that the sample is being sent.
NB: The sample should NOT be delivered to the laboratory via the automatic “Pod” system – it must be delivered by hand and the person delivering the sample to the laboratory (normally a hospital porter) should sign the form on collection of the sample.
On delivery to the laboratory, the specimen should be received by a biomedical scientist (BMS) who will check the correctness of provenance and labelling of the specimens. They will confirm receipt of samples and sign the LCOEF (there are separate guidelines for laboratory staff).