It opinion on what this evidence may

It is a common procedure for expert witnessesto give evidence in court within their proficiency, and give their opinion onwhat this evidence may mean or suggest.  Expertsare sworn into oath and are therefore required to tell the truth. However, astudy by Brandon L Garrett and Peter J Neufeld investigated connections betweenan expert testimony and the convictions, which then led to exonerations, due topost-imprisonment analysis of samples. Garrett and Neufeld found 156 cases andstudied the court transcripts. They found that 60 percent of those reviewedincluded a testimony that was deemed invalid.

They split the different types ofvoid testimony into six categories which included; “ non-probative evidence presentedas probative (meaning tending to prove), discounting exculpatory (meaningproving innocence, defending those convicted) evidence and the inaccuratepresentation of statistics” (8). Like all experiments, analysis tests have an error rate that is not zero. However, a report publishedin 2016, stated that expert witnesses often exaggerated claims, using termssuch as “ 100 percent certain”, “ zero” or “ vanishingly small” and these statementsare not scientifically valid (9). They are alsosubjective; what one expert may believe to be insignificant could be deemed asimperative to another, and such remarks could be confusing to the jury andothers present in the court. Within laboratories, there are certain standards that must be metin order to create valid and reliable results across the board. The UnitedKingdom Accreditation Service certifies that a lab is adhering to theseregulations at the ISO/IEC 17025 level. They test the “ continuity of evidence, management of case files and storage of exhibits. In addition, accreditationdetermines the competence of staff, the validity and suitability of methods, the appropriateness of equipment and facilities, and the ongoing assurancethrough internal quality control.

(4)” If a laboratory was to deviate from thesestrict criteria, a chain of problems will arise. Randox Testing Services drugand alcohol testing service which has used by police across England and Wales. In November 2017, the news broke that there may have been a manipulation ofdata within the company.

It was later revealed, by several newspapers, thatthis could have potentially affected over 10, 000 cases dating back to 2013. Twoemployees of the firm were arrested on suspicion of evidence manipulation.