NCJ Number
61456
Date Published
1978
Length
23 pages
Annotation
THE LX39 LATENT FINGERPRINT MATCHER, A COMPUTERIZED METHOD FOR AUTOMATICALLY DETERMINING IF A LATENT FINGERPRINT TAKEN AT THE SCENE OF A CRIME MATCHES AN INKED, ROLLED FILE FINGERPRINT, IS DESCRIBED.
Abstract
THE LX39 MATCHER USES THE X AND Y COORDINATES AS WELL AS THE INDIVIDUAL DIRECTIONS OF BOTH THE RIDGE ENDINGS AND BIFURICATIONS OF THE FINGERPRINT. EACH FINGERPRINT HAS ABOUT 80 SUCH MINUTIAE IN ITS RIDGE PATTERN. BY COMPARING THE ANGLES AND COORDINATE VALUES REPRESENTING THESE MINUTIAE, THE COMPUTER CAN DETERMINE WHETHER TWO FINGERPRINTS COME FROM THE SAME FINGER. IN CONTRAST TO OTHER MATCHERS WHICH COMPARE ONLY ROLLED PRINTS, THE LX39 LATENT PRINT MATCHER MATCHES LATENT PRINTS WITH FILE PRINTS IN A SEVEN-STAGE PROCESS: MINUTIAE SELECTION, TRIAL PAIR SELECTIONS, PAIR ORDERING, VERIFICATION OF PAIRS, RELOCATION OF THE SEARCH PRINT CENTER POINT, REREGISTRATION OF MINUTIAE, AND DETERMINATION OF A FINAL MATCHING SCORE. A TRIAL COMPARISON OF THIS SYSTEM AND A SEMIAUTOMATED SYSTEM DEMONSTRATED THAT THE LX39 MATCHER IS CAPABLE OF PRACTICAL APPLICATION IN A LATENT SEARCH SYSTEM, ALTHOUGH ITS PERFORMANCE IN A LARGE FILE OR THE NEED FOR AN EXPERT TO CONFIRM IDENTIFICATION CANNOT YET BE PREDICTED. TABLES, FIGURES, PHOTOGRAPHS, AND REFERENCES ARE INCLUDED. (CFW)