Finger Marks Techniques

Decent Essays
Finger-marks are known as a small print that can be left on any surface, each finger-mark is unique to an individual. There are multiple types of finger-marks the three main ones are known as a Whorl, Arch and Loops. The finger-marks are always photographed before being collected at a crime scene, there are several different types of techniques that are used to be able to lift the prints. There are hinge lifts, rubber lifts and cellophane tape.
Hinge lift can be used using multiple different colours backgrounds this to allow for the visualisation of the finger-marks so that they can be developed using different colour powders. The hinge lift is placed onto the finger-mark and is pressed down evenly over the mark, the lifted print is then covered
…show more content…
There will be 8 different finger-marks that will be used each time for each experiment that will take place. These prints will be created by one individual to be able to keep a constant pattern within the practical. There are two slightly methods that will be used, the first method is cyanoacrylate fuming the item that contains the print will be suspended within the tank this is to ensure that the item is exposed to the fumes. This process will take up to 45 minutes once the time is completed the whitish coloured print will appear on the item showing the finger-mark/s. The print can be enhance further using a fluorescent dye the fan is then turned on and is then used to circulate the fumes which will then increase the surface contact between the latent print residue and the cyanoacrylate vapours. A heating method will then be applied and the cyanoacrylate will be placed onto a dish and then a heating tool will then be placed onto the dish until it accelerates the polymerization process of the cyanoacrylate however there is a possibility that heating the cyanoacrylate will accelerate the volatility which then in turn will mean a faster vapour release which will then accelerate the recovery of the latent print. Another method that is going to be used within this practical is like the first method, however this current method will be using approximately 25 drops of liquid cyanoacrylate and this will then be placed into a magnetically locked in a shelf above the item that is about to be fumed. The fume cupboard will then be heated to 120 degrees with the humidity being maintained at 80 degrees. The heating and the humidity cycle will then take approximately 30 minutes, the fuming cabinet will need to take 20 minutes to remove any harmful residual vapours. Once this is complete the print that has been exposed by the fumes
Get Access