Fingerprints
When are fingerprints utilized?
Fingerprint identification is utilized at many levels of the process. Fingerprints are commonly used in relation to:
- Warrants and extradition: police officers and jailors use such identification to confirm a suspect's identity and to facilitate arrest.
- Charging decisions: Positive and negative conclusions on fingerprint identification evidence determine the strength of the case and the appropriate charges to file
- Jury Trials: Latent fingerprint examiners, which are the prosecution's expert evidence also use this type of evidence to conclude whether the fingerprints of the accused match those found at the crime scene.
- Appeals level: fingerprint identification evidence is used to bolster the prosecution's argument that the jury's verdict was appropriate and that any other alleged error at trial should be viewed as harmless error considering the strong weight of the fingerprint identification evidence.
Types of Fingerprints
There are two types of fingerprints:
- Rolled or inked prints: obtained by individuals inking their fingers and rolling each fingertip from edge to edge on paper - these are also called known fingerprints because the identity of the person is known when they are taken and
- Latent fingerprints: obtained by using fingerprint powder to make the latent print visible. Once the latent print is made visible, tape is used to lift the latent print from its original surface onto a lift card. These lift cards are examined by fingerprint identification experts who compare the friction ridge detail in the known print. Both types are utilized in the criminal justice system
Points of Match
Fingerprint experts reach a conclusion as to whether the fingerprints found at the crime scene match those of the accused on the basis of matching points'. At the moment there are no universal standards of matching points. Examiners historically have employed identification standards ranging from eight to sixteen matching characteristics, or "points of similarity." Yet, the FBI has stated that there should be no minimum standard and that the determination of whether there is a sufficient basis for an identification should be left to the subjective judgment of the individual examiner. The same is applied in the United Kingdom. On the contrary, other countries have set standards. For example, Australia has a minimum standard of twelve matching ridge characteristics whereas France and Italy have sixteen.
See Evidence
