The science of biometrics involves identification of people based on physical and behavioral characteristics. This includes facial recognition software, voice identification software and retina scanning. Biometrics is used commonly in forensic science with fingerprinting, handwriting analysis, hair analysis and blood identification.

Forensic Identification with Tattoos

Skin markings like scars, birthmarks and tattoos are considered soft biometrics, easily measurable physical characteristics that can change. Tattoos are becoming more common with estimates that approximately 36% of people between 18 and 29 have at least one tattoo. Most are specific to the individual, though many social groups adopt tattoos of similar design to designate membership. This is very common among gang members. Tattoos can give information on social characteristics such as time in prison, number of crimes committed and ethnic affiliations.

Tattoos have been used for identifying bodies in mass disasters like 9/11 and homicides. This is often necessary when partial remains are found or other identifying biometrics like fingerprints are removed. Residual markings from tattoos remain in the skin even after burns or decomposition. Tattoos are also used to identify suspects in custody who may be using a false name.