Fingerprint Identification
Materials
Procedure
Quantitative Evaluations
Data
Graphs
Results
Conclusions
Sources of Error
Thanks
Bibliography
Previous Projects
Two prints must have the same general pattern in order to give a positive identification. They must also have a certain number of common ridge characteristics. This number can vary depending on how common the characteristics are and how much of the print is available.
There are two main methods that are used for fingerprint identification. Minutiae-based techniques first find minutiae points and then map their relative placement on the finger to match ridge characteristics. It is difficult to extract the minutiae points accurately when the fingerprint is of low quality. Also this method does not take into account the global pattern of ridges and furrows. The correlation-based method is able to overcome some of the difficulties of the minutiae-based approach.
Correlation-based techniques require the precise location of a registration point and are affected by image translation and rotation.
Fingerprint details are described on three levels. Level one detail includes the general ridge flow and pattern configuration. The details are not sufficient for individualization but can be used for exclusion. They may include information enabling orientation, core and delta location and distinction of finger versus palm. Level two detail includes formations and ridge characteristics. The relationship of level 2 detail enables individualization. Level three details include all dimensional attributes of a ridge, such as ridge path deviation, width, shape, pores, edge contour, incipient ridges, breaks, creases, scars and other permanent details.
Fingerprint classification has evolved since the invention of computers. The Henry Classification System was followed by the Automated Fingerprint Identification System (AFIS) that is a database for prints scanned into the computer. Departments input fingerprints from all arrests into the national database in hopes that they might find a hit in the records.
Fingerprint Basics
Types of Fingerprints
Fingerprint Patterns
Ridge Characteristics
Developing Powders
Developing Reagents
Developing Reagent Details
Lifting Techniques
Unusual Fingerprints
History of Fingerprinting
Body Prints
Animal Fingerprints
DNA Fingerprinting
Trace Evidence
Forensic Science
Jobs Involving Fingerprinting
Fingerprint Identification