Identifying Drugs of Abuse Using Gas Chromatography :: Forensic Science

Scenario On the 23rd of September 2015 at 22:58, Mr. Rob Slone was arrested on Sanctuary Road, West Bridgford on possession with intent to supply. A large amount of cash was found on the suspect and a bag containing unknown tablets and powders was recovered from the riverbank, in close proximity to the location of the arrest. A balance with off- white powder, an off- white powder in self sealed bag and a tablet in paper wraps were seized from Mr. Slone's property. At the riverside, a  £5 note, a tablet in paper wraps and 2 off- white powders in self sealed bags, were seized. Physical examination Aim The evidence is physically examined to determine the integrity of the seized substances before any destructive techniques are used. Introduction In forensic science physical examination of the evidence is essential as if the packaging is not correct evidence can be lost or accessed. A chain of custody is important Photography is essential, any photographs should be taken before the evidence is moved. Methods Exhibit MF/2 Before any destructive techniques were used on the exhibit, the integrity of the packaging was determined. The tamper evident bag containing the exhibit was examined to check if was correctly labelled and sealed. Upon receipt of the exhibit the continuity label was signed to ensure the integrity of the exhibit. The tamper evident bag was cut and opened. The yellow paper wrap containing the white tablet measured 1.8x 4cm. The yellow paper wrap was opened to remove the tablet. The exhibit MF/2 was photographed with scale. Visual examination indicates that the exhibit is a white tablet with a manufacturer’s logo CO/COD. The imprint suggested that the tablet could be co-codamol. Co-codamol The tablet was weighed in a plastic weighing boat to prevent any contamination. The tablet weighed 0.6001 grams. All the information was noted on a General Examination Record. Exhibit DR/3 Upon receipt of exhibit DR/3 the continuity label was signed. The tamper evident bag was cut and opened. In the bag there was an off white powder in a sealed bag. The bag containing off white powder was weighed. It weighed 0.80823 grams. Results and discussion Physical examination is essential for the integrity of exhibits. The exhibits must be physically examined before any techniques that would destroy are used. The exhibits The aim of the experiment as a forensic analyst is to examine the seized items visually before the presumptive tests. Exhibits Bag Number Samantha Naas DR/3 D10025448 MF/2 D10025224 Catherine Tuckey DR/2 D10025606 MF/3 D10025590 Lee Berry DR/1 D10025639 MF/4 D10025438 Presumptive tests Aim The presumptive tests are carried out to get a preliminary identification of the controlled sample and are used for qualitative analysis of the unknown substance.