Fingerprints are unique to an individual, even in identical twins, although they possess the same DNA.
They are used to identify individuals for many reasons although through the different areas of the media, identifying perpetrators of crime is the one that the general public are most familiar with. The first occasion that fingerprint evidence was used in England was in 1902 at the Central Criminal Court in London.
They are used for different reasons including the identification of persons involved in unfortunate disasters such as tsunami's, air, rail and vehicle accidents where the usual means of identification are unable to be used. Identifying victims of crime and eliminating persons with legitimate access to houses, offices and other premises when they have been subjected to criminal activity are among other uses.
Modern technology is now able to use fingerprints to access mobile telephones, computers and access various security areas of buildings instead of key fobs and cards which can be lost and removing the need to remember many numerical and letter door codes.
Generally fingerprints can be taken two ways, either using equipment such as 'livescan' where the fingerprints are taken and transmitted digitally or manually using ink.
Many different features are used when making fingerprint identifications and when sufficient are found in agreement there can be no doubt that both impressions under comparison have been made by the same finger or palm.
A number of techniques exist for detecting and enhancing fingerprints depending on the surface requiring examination.
Not everyone is a good 'donor' of fingerprints nor is every surface conducive to retaining fingerprints. How much a person perspires, atmospheric conditions and receptiveness of a surface are all factors that contribute towards the outcome of a fingerprint examination.
It is the sweat 'left behind' on a surface when touched by the 'finger' that reveals an impression when examined.
The most commonly used technique for developing fingerprints on a surface is by powder. Two powders are generally used - flake and granular. Flake is the more sensitive.
These powders generally require the surface for examination to be clean, dry and even.
Although mainly water, sweat also contains additional constituents.
Depending on the surface being examined, different techniques and enhancements may be employed for detecting fingerprints. These can include chemicals which react and/or stain these additional constituents thus producing images that can be photographed and used for comparison against sets of fingerprints taken from persons in a controlled manner.
These include, amongst others, Ninhydrin and DFO (Diazafluorenone) which are used commonly
Assessment of Fingerprint Evidence
Allegations of fingerprint planting and forgery
Location of fingerprint significance
The fingerprint team at Formedecon have carried out thousands of cases involving fingerprint and palm print evidence.
We have significant experience in examination of prints for identification of suspects and used location of prints to show the direction of movement of someone through a crime scene. Fingerprints can also be used to determine a manner in which a document has been handled and have been involved in cases where the positioning of fingerprints associated with questioned signatures forms the basis of defence and led to acquittals. Our experts can attend and take prints from individuals when required, obtain prints from exhibits and carry out a full comparison.
If you have a case involving fingerprints their identification and/or location or you need advice from any of our forensic scientists, then give us a call or contact us by email for advice.