Fingerprints

Fingerprints are a well known method of uniquely identifying a person. Even identical twins have different fingerprints.

Fingerprints are made up of a series of whorls, loops, ridges and arch formations as are the palms of the hands. During a missing persons investigation the police may send forensic officers to the missing person’s home to attempt to obtain fingerprints from surfaces or their personal possessions.

On hard surfaces fingerprints will either be patent (visible) or latent (invisible). Patent prints are formed when a liquid is transmitted to a surface by a finger, i.e. the process of fingerprinting produces patent prints. Latent prints occur when natural oils from the body are left on a surface. Latent prints are not usually visible to the human eye and detection can require the use of other agents. Fingerprints can also be found on soft surfaces (such as wet paint or soap) and these will often be three-dimensional prints.

Fingerprints can be very fragile, especially on certain surfaces, so forensic officers will use specific techniques to detect them. Officers may use ultraviolet light to ascertain if fingerprints are present on surfaces where they may not be easily visible or may brush over surfaces with magnesium powder to display prints. There are also a variety of other collection methods available.

The collection of fingerprint samples can be messy and forensic officers may not clean the surfaces when they are finished. Some people may find this process distressing and you may want to consider asking a friend or family member to stay with you to support you while the forensic team is in the home, and to help clean up after they have gone.