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The Fingerprint Science and Ridgeology (The following paper was presented at the August 6, 1994 SCAFO meeting)
By KURT E. KUHN The information contained in this paper is a review of an in--depth research project published and presented by Sgt. David R. Ashbaugh of the Forensic Identification Support Section of the Royal Canadian Mounted Police; “RIDGEOLOGY -- Modern Evaluative Friction Ridge Identification”. As a result of his research, the R.C.M.P has incorporated the use of “Ridgeology” into their forensic examination of friction ridge structure. Additional research and application here in the United States has recently resulted in the identification of a latent print which contained three (3) “Galton Details” by the Federal Bureau of Identification. The science of fingerprint identification has been undergoing dramatic changes over the past two decades. First came the introduction of the new latent fingerprint processing techniques. These new processing techniques were soon followed by the advent of the Automated Fingerprint Identification Systems. Now, latent print examiners are being introduced to additional available identification methodologies. Ridgeology is a method of evaluating all friction ridge structure. It is based upon scientific principles and procedures that have been established and verified through years of research. The term Ridgeology refers to a forensic identification science that is associated with any and all ridge detail on the volar areas (bottoms of the hands and the feet) and not just formations that appear in these areas. Ridgeology incorporates the use of a number of physical sciences as well as the identification sciences of edgeoscopy and poroscopy as it addresses the whole ridge detail spectrum. Ridgeology attempts to explain how and why friction ridge structure differs from individual to individual rather than depending upon the explanation of the basic laws of chance. Ashbaugh interprets the examination of friction ridge structure in three levels. The first level is that of an evaluation of the pattern or ridge configuration present. The next level consists of an examination of the shape and location of the various minutiae and other accidental characteristics such as scars or areas of disassociated ridges. The final level utilizes both edgeoscopy and poroscopy in an evaluation of the shape and location of each ridge unit both as an individual unit and as a whole. Edgeoscopy was first presented in 1962 by Salil Chatterjee of India. Chatterjee envisioned an identification process where characteristics along the ridge edge would be compared and evaluated for comparison purposes. These characteristics are the result of the alignment and shape of the individual ridge units as well as the pores close to the edge of the ridge. However, these shapes are only of use when the friction ridges are clearly reproduced in both the latent and the exemplar prints. Poroscopy was established by Dr. Edmond Locard of Lyons, France in 1912. Locard was of the opinion that friction ridges could be identified by comparing pores. Locard suggested that identification could be based upon the size, shape, relative position and the frequency of the pores. His opinion was that the agreement of 20 to 40 pores was sufficient for a positive identification. Historically, the pore structure present in most crime scene prints and inked prints is not sufficient for comparison and evaluation. However, with the introduction of the new latent print technology, the comparison of relative pore locations is feasible. It is also sad to note that, with the development of Live Scan and Electronic Fingerprint Imaging, this new technology may be removed from the forensic identification discipline just as it was being introduced. A significant part of Ridgeology is understanding the “Science of Fingerprint Identification.” What makes fingerprint identification a “science”? In most early academic training in the forensic fingerprint discipline, we were taught that dactyloscopy was defined as the “science of fingerprints.” As I began to research this presentation, I discovered that the term dactyloscopy was not necessarily correct. The word dactyl is derived from the Greek word daktylos meaning finger. Dactyloscopy, as defined by Webster, is the classification of fingerprints. However during my review and discussion with colleagues, I came across another definition that appears more appropriate. Dactylography, as defined by Webster, is the “scientific” study of fingerprints as a means of identification.
Fingerprint examiners may not always realize it but they complete each
of the steps that are followed in a routine scientific procedure. Each
examiner initially conducts an “ANALYSIS”, then a “COMPARISON” , followed
by an “EVALUATION” and finally a “VERIFICATION”. These scientific aspects
can easily be related to fingerprint identification.
* ANALYSIS
* COMPARISON
* EVALUATION
* VERIFICATION Fingerprint Identification is based upon the applications and interpretations of several natural sciences.
* Anatomy
* Genetics
* Chemistry
* Neurology
* Mathematics Everyone in this forensic discipline is aware of the principles of fingerprint identification, as we are routinely describing them to the juries during our testimony.
Uniqueness Based on the previous information, Fingerprint Identification can be defined as “an applied science that is objective in nature with a subjective opinion being rendered as a conclusion.” Some additional clarification from Webster may be necessary to fully understand this definition. “Objective” is defined as “without bias or prejudice.” “Subjective” is defined as “personal.” To simplify the wording, Fingerprint Identification is an applied science that is without bias or prejudice with a personal opinion being rendered as a conclusion. It also appears as though some of our academic training in the history of fingerprint identification has been lacking. Most everyone involved in the discipline recognizes the names Marcello Malphigi, Sir Francis Galton, Sir Edward Henry, Henry Faulds and Johannes Purkinje. But there are several other researchers who have made significant input into our field. In 1904, Miss Inez Whipple, a Zoology professor at Smith College in Massachusetts, published a research paper entitled “The Ventral Surface of the Mammalian Chiridium”. This paper addressed the evolution of friction skin. It should be also noted that several other similar research projects were conducted prior to the start of this century. (Galton 1892, Kollman 1883, Klaatsch 1888, Reh 1894, Blaschko 1884, Hepburn 1895 and Wilder 1897). Whipple's paper was considered a landmark in the field of friction ridge identification and genetics. In 1929, Harold Cummins, an Anatomy professor at Tulane University School of Medicine in Louisiana, published a paper entitled “The Topographic History of the Volar Pads in the Human Embryo”. Cummins' paper describes the development of the volar pads at approximately the sixth week and development of friction ridge structure at about the 13th week. In 1952, Alfred Hale, also from Tulane University, published a thesis entitled “Morphogenesis of the Volar Skin in the Human Fetus”. Hale's paper described the development of the friction ridges. His research also indicated the formation of these ridges at approximately the 12th or 13th week. He also established the role of pore structure and the development of the secondary layer of ridges. It was his theory that friction ridge volar patterns are subject to both genetic and physical factors. In 1976, Michio Okajima, a professor from Japan, published a paper entitled “Dermal and Epidermal Structure of the Volar Skin”. His research established the double rows of dermal papillae present under the surface of friction ridges. The primary importance of his research was that incipient ridges are, in fact, permanent friction ridge structure. In a recent high profile murder trial in the Los Angeles area, questions were asked regarding the research that had been conducted regarding the individuality of friction ridge structure. Those examiners testifying in the case were able to identify several of the above individuals, thus defusing a possible challenge to the training and knowledge of the examiners involved.
This article was originally published in “THE PRINT” |