Using material to fight crime
Collecting fingerprint evidence
Fingerprint evidence can be collected using powders:
- on a white surface use carbon black powder;
- on a black surface use aluminium powder.
The powder is dusted on and then any excess powder brushed off.
A piece of cello tape is then used to transfer the print onto card or a glass slide for further analysis.
Visualising fingerprint evidence
Fingerprints can also be visualised using alternative light sources, such as UV light or chemical developers, such as iodine fumes.
A photograph or scan of the fingerprint can then be compared to a database of fingerprints to identify an individual.