What is AFIS?
The Automated Fingerprint Identification System, or AFIS as it is most commonly referred to, is a computerized system for entering, storing, searching, retrieving and matching fingerprint and palm print images. The DeSoto County Sheriff’s Department AFIS Unit began operation in October 2009 and is capable of storing one quarter of a million fingerprint and palm print images in its database.
Why Fingerprint Identification?
Fingerprints are developed during the third month of gestation and remain unchanged until after an individual’s death. The science of fingerprints is based on the fact that no two fingerprints are the same. Even after billions of human and automated computer comparisons, no two fingerprints have ever been found alike. Therefore, fingerprints offer an infallible means of personal identification.
Fingerprint identification remains the most commonly used forensic evidence in the world. In most jurisdictions, fingerprint examination cases match or outnumber all other forensic examination casework combined.
How does AFIS work?
When an individual is arrested and brought to the DeSoto County Jail, they are fingerprinted as part of the book in process utilizing a Live Scan Terminal. Their fingers and palms are rolled on a glass plate located on the Live Scan Terminal and a scanner located below the plate captures a high quality image of those prints. The prints are checked by a trained Identification Technician as part of our quality control process after which, they are electronically transmitted to the AFIS unit. After submission to the AFIS unit, an AFIS Specialist reviews each print checking for the proper orientation and characteristics before it is submitted to the main database.
After checking the prints, the AFIS Specialist transmits the fingerprints or palm prints to the AFIS system where they are searched against all of the fingerprint records contained in the DeSoto County Sheriff’s Department database. Within minutes, AFIS returns information on the twenty (20) closest matches to the prints searched. The AFIS Specialist compares the known prints of the individual arrested to the prints returned from AFIS to determine if they have a previous arrest, an active warrant or if they provided false identifying information at the time of their arrest or during the book in process.
How does AFIS work to help Investigators solve crimes?
Investigators or Crime Scene Technicians collect suspicious (unknown) fingerprints or palm prints also known as “latent prints” as evidence at the scene of a crime. Once collected and properly documented, the prints are submitted to a Latent Print Examiner of the DeSoto County Sheriff’s Department AFIS Unit for forensic examination. If the latent print is of sufficient quality, it can be entered into AFIS, where it is compared with all of the fingerprints in the database.
The AFIS computer generates a list of “candidates” whose known fingerprints bear similarities to the latent print being searched. A latent print examiner evaluates the AFIS candidate list and compares these prints to determine if they match. The latent print examiner will then make a direct comparison between the actual evidence fingerprint and the fingerprint card bearing the most similarities to determine if they match.
If they match, the suspect is identified. This is considered an AFIS “hit”.
Since AFIS databases are constantly being updated and compared, AFIS can help solve a crime which occurred years ago.
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