SDFL Impression Evidence
AFIS IAFIS Impression Evidence FAQ
Fingerprints, palm prints and foot prints are impressions of the friction ridge skin present on the palm side of the hand and soles of the feet. When a person touches, grabs, or walks barefoot on a surface an impression of the friction ridge skin may be left behind. These unintentional impressions are called latent prints.
Examinations conducted in the Impression Evidence section of the lab include:
- Process evidence from crime scenes for the presence of latent prints.
- Examine latent fingerprint lifts from crime scenes for the presence of latent prints.
- Photograph developed latent prints.
- Compare latent prints to known suspects and/or victims.
- Utilize AFIS and IAFIS for no suspect cases.
- Compare known (record) fingerprint cards in habitual cases.
The importance of latent print evidence is its ability to identify an individual. Latent prints can be identified to a single person because of the friction ridge that skin possesses. The two key properties of friction ridge skin are: permanence and uniqueness. The friction ridge skin forms before birth and does not change naturally, except to grow larger, until after death. With the exception of injury, a person has the same fingerprints, palm prints, and foot prints from early gestation until decomposition after death. Additionally, the friction ridge skin has unique characteristics which allow even small latent prints to be identified to a single person, in some instances.
Latent prints left on a surface can be visualized through a variety of chemical and physical development techniques. Once visible, the latent print can be photographed and compared to the known inked fingerprints (or palm prints or foot prints) of an individual. Through careful analysis and comparison of the friction ridge skin characteristics in both the unknown latent print and the known inked print, a person can be identified, or eliminated, as having made the print.
If the origin of a latent fingerprint is unknown, it may be searched through the Automated Fingerprint Identification System (AFIS) database. The South Dakota AFIS system is a part of the Midwest Automated Fingerprint Identification Network (MAFIN). MAFIN is a computer database which stores the images of inked record fingerprints from North Dakota, Minnesota, and South Dakota. When an unknown latent fingerprint is searched through the database, a list of possible candidates is generated and reviewed by a Criminalist. If a candidate is not identified through an AFIS search, a latent print may also be searched through the FBI’s Criminal Justice Information Services (CJIS) Division's Integrated Automated Fingerprint Identification System (IAFIS) database. The IAFIS database contains more than 35 million individual’s known record fingerprints. IAFIS like AFIS generates a list of possible candidates that then must be reviewed by a Criminalist.
Reports are issued to agencies submitting evidence to the SDFL regarding the results of latent print examinations and Criminalists may be called upon to testify in courts throughout the state of South Dakota.
( Automated Fingerprint Identification System)
The introduction of the Automated Fingerprint Identification System (AFIS) in 1997 has allowed Criminalists in the Impression Evidence Section of the Forensic Lab to scan latent fingerprint images into the database to search the record fingerprint cards on file in the Midwest Automated Fingerprint Identification Network (MAFIN). MAFIN includes all the record fingerprint cards on file in the states of North Dakota, Minnesota, and South Dakota.
AFIS gives the capability of real-time identification of a suspect in investigations, based on latent prints found at the scene of a crime for no suspect crimes or when a potential suspect has been eliminated as the source of a latent print.
The Forensic Lab upgraded to a new AFIS system in 2008. The new upgrade has allowed Criminalists to not only search latent fingerprints in the system but to also search latent palmprints that are found at the scene of a crime.
(Integrated Automated Fingerprint Identification System)
The FBI's Criminal Justice Information Services (CJIS) Division's Integrated Automated Fingerprint Identification System (IAFIS) provides the Forensic Lab an opportunity to search latent fingerprints against the largest criminal fingerprint repository in the world, which contains more that 35 million individuals known fingerprints.
The Forensic Lab is authorized to search latent fingerprints against IAFIS after an unsuccessful AFIS/MAFIN search. IAFIS currently does not have the capability to do palm print searches.