The role of DNA, fibers, cartridge cases is increasingly important in the real world of criminal defense. Lawyers must have an understanding of forensics in order to discredit evidence or to use it  to their clients’ advantage. Crime scenes are messy. There are plenty of opportunities for mistakes to be made in the collection, handling and transportation of evidence. 

The demise of the Forensic Science Service comes as police forces shift towards a more streamlined approach to the use of forensics in criminal cases. Instead of courts being presented with extensive forensic reports that cover all the evidence recovered in police investigations, only short reports with the initial and key findings will be submitted. Prior to the trial, prosecutors will present the defence with evidence incrementally and order additional forensic tests only when the case requires them. For example, the defence may concede a case when prosecutors present a DNA fingerprint that links the defendant to a crime, negating the need for further tests. At each stage, the defence has an opportunity to dispute the evidence before the case goes to court.

Lab analysis: The results are only as good as the equipment and the technicians Laboratories must be certified to undertake particular types of analysis. Sophisticated equipment must be properly calibrated. Records must be accurate. Technicians must be properly trained. Just as with evidence collection, proper procedures for evaluating the evidence must be followed and standards must be met. Even a slight deviation can lead to evidence contamination.

Analysis and testimony: Challenging the prosecution's experts when the prosecution calls in a technician or an expert in a certain field to testify and introduce evidence, explain its importance and how it was analyzed and offer interpretations and conclusions. It is the criminal defense lawyer's job to challenge any studies, facts or figures offered by the expert witness during cross examination: What are the expert's credentials? Is the supporting information sufficient or reliable enough to draw a certain conclusion? What is the scientific basis for the finding? When pressed, these experts may not be able to justify their findings. At other times, the defense may call a witness of its own to offer conflicting testimony.

Prepared By: THAN CHONG SENG (JOHNSON)   A122879

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