Fingerprints identified at crime scenes fall into three categories:
- Patent
- Latent
- Impressed
Patent Fingerprints are those that are clearly visible to the naked eye and are normally made because the individual has had their fingers in some sort of liquid or powder . Mostly this would be blood, ink , oil or the likes and the fingerprint is clearly visible and a close up photograph is often all that is necessary to record it.
Latent fingerprints are prints that are not visible to the naked eye but are visible under certain conditions; they can be made visible – or certainly more identifiable – by introducing them to a powder or chemical agent.
Impressed prints are those that have been made in soft material or tissue by pressing down with the finger or hand. These prints can be photographed or in certain circumstances moulds made if they are very fragile.