Forensic fibres analysis often assumes an important role in any crime scene investigation. Fibres are often regarded as the most common and integral part of evidence located at the scene of a crime. They can give intelligence on the perpetrator of a crime, what that person was wearing at the time and also what sort of contact there was between the perpetrator and the victim.
Most items of clothing are made out of tiny fibres almost invisible to the naked eye and when two people come into contact those minute fibres may be transferred between them. There are three basic fibre groups: vegetable fibres (cotton, flax and linen) animal fibres (wool) and man-made fibres (polyester and nylon).
Connecting a suspect to a crime by collecting and analysing trace evidence like fibres is a very specialised undertaking and fibres which appear very similar in colour to the naked eye can often be discriminated by a fibres expert using their specialist expertise and a series of forensic instrumental tests. The presence of ‘foreign’ or non-constituent fibres on clothing has played a key role in many criminal convictions. However, as with all types of trace evidence, issues continue to be raised about potential cross contamination of items in the aftermath of a crime.
The position of fibres and the way they have been deposited on a surface can also provide intelligence as to what may have happened at a crime scene. For example if fibres are found in balls on the surface of a carpet, it may indicate that something heavy (such as a dead body at a murder scene) had been dragged across it forming those fibrous balls.
A woman is discovered in her bedroom, having been strangled to death. Her clothing is sent to a forensic laboratory for examination for trace evidence including fibres. ’Foreign’, non-constituent fibres which are navy blue in colour are found on her clothing. Clothing seized from a suspect includes a navy blue woollen jumper and the Crowns forensic scientists report indicates that the fibres in the jumper are similar to those found on the victims clothing. Issues are raised pre-trial about possible contamination issues surrounding the murder scene as the first person at the scene was also wearing a navy blue woolen jumper and no protective clothing.
Our fibres experts have years of experience in recovering and examining fibre evidence and in interpreting its significance. We can:
Review the Crowns fibre evidence and forensic report.
Re-examine the victims clothing, the fibres previously recovered from the victims clothing and the suspects clothing and reassess all the fibre evidence.
Examine the navy blue jumper worn by the first person at the scene to see if that jumper could have contributed in any way to the navy blue foreign fibres found on the victims clothing.
Appear for the defence council as an expert witness where they will ensure that the true value of the prosecution’s evidence is explained in a clear and credible manner with other possible interpretations put forward for the benefit of the courts.