Forensic Biology is the application of biological analytical methods to legal investigations. It involves the examination of evidential items and/or scenes of crimes for different body fluids, hairs, fibres etc which could link certain individuals to those items or locations.
There are several types of bodily fluid that may be found at a crime scene or on the clothing of a victim of a crime, which have the potential to be analysed and used to help identify the perpetrator of that crime. Bodily fluids fall into two categories, namely excreted fluids e.g. faeces, vomit, bile and sebum (skin oil) and secreted fluids e.g. blood, semen, female ejaculate, saliva and urine.
The examination of such bodily fluids may not only provide evidence about the identity of the offender, but can also help to provide information about the sequence of events which occurred before, during and after a crime was committed or in some cases whether any crime had been committed at all. For example the presence of semen may suggest a recent sexual encounter, whether consensual or not.
The presence of blood at a crime scene at a crime scene indicates some form of physical struggle, assault or murder took place. However, analysis of the distribution of that blood at the scene (bloodstain pattern analysis) or on the suspects and victims clothing and other items can assist in determining who participated in the attack and who was just a bystander or who assisted the victim after the event.
The presence of certain biological materials (e.g. blood, saliva, semen, skin cells or hair) at a crime scene or on the clothing or person of the perpetrator and/or the victim could be a source of DNA, which can be profiled. A particular individuals DNA profile can then be compared with any DNA recovered from biological materials, to determine whether that individual may have been present at the crime scene.
It is vital that the information derived from biological evidence should be set in the context of the circumstances of the incident and interpreted appropriately in conjunction with findings from other forensic disciplines.
Forensic Equity’s forensic biologists have years of knowledge and experience, making then eminently qualified to provide sound and credible forensic analysis and interpretation.