Introduction to Forensic Science: Coursework Assignment

The Scenario:

Joe Soap was apparently found dead in his living room by two acquaintances, Bernard White and Arnold Brown. He had been stabbed twice in the chest with a kitchen knife, and there were signs of violent struggle at the scene. SOCO recovered various items and material from the scene.

In the laboratory session these items and materials were analysed by specific methods. The laboratory session comprised of four separate but linked activities involving the items and materials collected by SOCO. Each session contributed in aiding me find the Joe Soap killer. The first activity involve the lifting and comparison of fingerprints. During this activity we were shown the steps taken in finding fingerprints and then lifting them, as fingerprints are one of the most useful types of forensic evidence (because they are unique to an individual and are often left inadvertently at the crime scene by the perpetrator). In terms of the case of Joe Soap a partial fingerprint was found and lifted from the handle of kitchen knife. This partial fingerprint was identified as being from Arnold Brown. The way this print was found to belong to Arnold was by finding as many comparison points as possible on the control and the found partial print. In this case there were the central pocket loop whorl with two deltas. The difference between the control print from Arnold and that of

Bernard was the shape of the central pocket loop whorl. As Arnold’s print was found on the knife found, he is automatically place at the crime scene and his lullaby (that he had found Soap dead) does not fit.

The next activity involved the examination of suspect fibres. The suspect fibres (from Soap’s, White’s and Brown’s jumpers) were found on tape lifts, they were then individually removed and mounted on glass microscope slides for more detailed examination and comparison with control fibres from the various garments. This close examination brought us closer to what may have happened at the crime scene. Arnold jumper was made of brown lambs wool which contained short brown fibres. The sample from his jumper showed that there were some long red fibres which were not from the original jumper. There was no white fibres meaning contact with Bernard must have been limited whilst contact with Joe(mostly long red fibres) may have occurred. Joe’s Soap’s jumper (red) was made of combination of cotton (48%), aquilic (48%) and nylon (4%). Joe’s jumpers contained short brown fibres, which looked very similar to those from Brown’s jumper. Laboratory examination can be used to identify the fibre type and determine the possible origin of the fibre from a fabric source. Overall the fibre identification suggested that Arnold and Joe may have come into contact at one stage.

The third activity involved the footwear marks found on the two floor tiles, recovered from the scene of Soap’s murder. The two marks were compare with the two controls provided by the suspects White and Brown, who claimed to have found Soap dead. Both suspects footwear print were found at the scene, with bloodstains. These bloodstains are very important as they aid us in to finding the time the suspect were on the scene. Footwear prints are made of a combination of dust, moister, and other practicals. The bloodstains found by Bernard’s footprint were smudged indicating

that Bernard had been at the crime scene after the bloodstains were created so its possible his lullaby is correct. However Arnold’s footwear print was found to have been created before the bloodstains were made, placing him at the crime scene before the murder.

In the final activity involved a preliminary identification of suspect powders found in the suspects cars and homes and also in the decease’s home. This Preliminary test showed that the powers found from Arnold and Soap had similar reactions. These reactions were very similar to that of cocaine and they had similar peeks. The major peeks and minor peeks were extremely similar showing that the substance may have been linked and from the same source.

Looking back at the practicals I can say that the activities have pointed in Arnold Brown direction placing him at the scene of the murder when he denies it.