Biologists also frequently work with other sections, such as the Specialised Fingerprint Unit, Explosives and Firearms sections to maximise the potential of all evidence.
Primarily they are involved in the following case types:
Offences against the person, such as:
- Rape/ Sexual Assaults
Volume Crime, such as:
- Theft/ Burglaries
- Drugs Offences
- Car crime
And any other crimes where fibres, body fluids and/or DNA are a possible evidence type.
Within these cases they examine the following evidence types:
DNA analysis at FSNI is carried out using DNA17 testing systems which analyse nuclear DNA. The significance of results of these analyses can be determine using statistical methods and interpretation software such as STRMixTm
Blood examinations are carried out in the laboratory and at scenes. Weapons, clothing and other items are examined. As well as examining for blood and interpreting patterns found, DNA profiling is used to identify a possible source of any blood.
Semen examinations are also carried out in the laboratory, on clothing, intimate swabs and other items, and at scenes. Presumptive chemical tests are used initially followed by microscopic confirmation. Again DNA profiling can be used to identify a possible source of any semen recovered.
Laboratory based examination only. Carried out using presumptive chemical tests. DNA profiling can then be used to identify a possible source.
- Urine /Faeces
Less common examinations carried out using chemical presumptive tests. Again can be used with DNA profiling to identify a possible.
Examined to determine if they are human in origin and their suitable for DNA examination. If not suitable they can be referred to other facilities for mitochondrial DNA testing.
- Fibres – Forensic comparison of fibres.
Carried out using high powered comparison microscopy with UV fluorescence, microspectrophotometry and FTIR.
- Contact DNA
As well as obtaining DNA profiles from identified body fluids profiles are also obtained from possible ‘touch DNA’, i.e. samples recovered from an area that it is suspected a person may have touched, for example the handle of a weapon. All DNA profiling is carried out using DNA 17 technology. Profiles produced can then be compared with reference samples from a person or with the local or national DNA database. Y-STR profiling is also under development.
- Damage –
Clothing /material can be examined for potential damage, to determine if it occurred during an incident or as a result of normal wear. Damage can also be examined to determine the force used or the implement involved, for example, knife damage versus that cause by scissors. It can highlight an area for the recovery of cellular material, i.e. grab areas. The cellular material can then be submitted for DNA analysis.
Other biological materials can be recovered for future examination by other specialists or research institutes.