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Special Review
Kurt E. Kuhn
The field of Friction Ridge Skin Identification is a complex subject. It involves a variety of sciences, empirical knowledge and jurisprudence. Occasionally, identification personnel with limited training and experience can be misdirected by individuals who lack the thorough understanding of all these various aspects. The case report in review, with the limited scope of its research, illustrates the problem of opinions and guidance by persons lacking the complete and integrated knowledge of the entire subject area. During the 1991 California State Division of the International Association for Identification's Annual Training Seminar, the case report in review was submitted for distribution to the seminar attendees. The case report was reviewed and a question was raised as to the scientific accuracy of the test performed. The Science and Practices Committee was assigned to investigate the article and case. The committee's investigation included written correspondence and telephone conversations with the author, James F. Schwabenland, Deputy District Attorney William Yoshimoto, and Deputy Attorney General Shirley Nelson. Copies of Mr. Schwabenland's testimony at both the preliminary hearing and trial, the Respondent's Brief prepared by the California State Attorney General's Office during the appeal, and the opinion rendered by the Fifth District Court of Appeal were obtained and studied. This special review is the result of that investigation. "Determining the 'age' of the latent finger or palm print residue on a particular piece of physical evidence is generally not possible" [2]. Mr. Schwabenland's opening statement is commonly accepted and supported by well-trained, experienced examiners, and by literary references. Cowger states "Latent print examiners seldom consider the age of prints. The reason for this is quite simple. Evidence prints can be composed of almost any material. The effects of time and environment on these components, although perhaps determinable by sophisticated laboratory techniques, are generally unknown to the average latent print examiner" [3]. Mr. Schwabenland's opinion that "all relevant factors were known and every effort was made to insure complete accuracy" [4] is faulty. He attempted to recognize, gather and consider some of the various factors necessary to establish the experiment's basis. He has considered the effects of time and environment and, in the experiment, has made efforts to duplicate those factors. However, the variables in the composition of the latent print residue were only partially recognized and addressed in a limited manner. The author proceeds in the experiment with the premise that the latent print residue was either natural perspiration or contaminants from the fried chicken. He failed to recognize, in the experiment, the existence of other possible latent print constituent variation. According to Olsen "There is a demonstrable difference between the secretion of the sweat glands on the papillary ridges of the hands and fingers and the secretions of the hairy portion of the body skin-the scalp, face, and neck, etc.-which contains secretions of the sebaceous glands" [5]. Along with these demonstrable differences within the individual's own various types of exudes, an individual's metabolism, as well as his emotional and physical condition, will also affect the quantity of exude. Although the author has considered the presence of contaminants from eating chicken, he failed to account for the possibility of other type contaminant or combination of contaminants, or even the variation of the residue naturally secreted by one person as compared to another. During the experiment no "sophisticated laboratory procedure", as Cowger suggests, was conducted. The sophisticated laboratory procedures would first need to include the determination of composition, viscosity and quantity of the latent print residue. Without this knowledge, the evaporative rate could not be established. If one were able to determine these variables, then a duplication of environmental elements could be administered to complete the experiment. Lacking these variables, no testing or experiment can be considered as complete or accurate. The well-trained, experienced examiner will gain the empirical knowledge that impressions aged several days (and longer) will occasionally "pop out" and possess clear well-defined ridge detail. If all the variables could be determined, scientific protocol would suggest three additions to the format of any experiment this significant: 1) The use of a blind (or even double blind) testing to ensure objectivity; 2) A sufficient sampling to establish the repeatability and consistency of the results and; 3) Adequate photographic documentation to ensure that any other examiner could reach similar conclusions when reviewing all the material. Review of the preliminary hearing transcript lacks any reference to the fingerprint as being "fresh" or any effort to establish the print's age. A review of the trial transcript provides the following excerpts. These are the listings which make reference to the print as being fresh, and no record of the experiment could be found in Mr. Schwabenland's testimony. The defense did not offer a challenge to the testimony or during cross examination. The defense attorney either lacked realization of the testimony's novelty, or in light of other overwhelming evidence, elected to concentrate the defense in other areas. It should be noted that the review by the Appellate Court indicates that "analysis of Gonzales Ruiz's stomach contents revealed that she had eaten chicken within three hours of her death" [10]. Additionally, there were uncontroverted witnesses to establish the date of the beer drinking and chicken dinner. According to the attorney who handled the appeal, the issue of the "fresh print" was not significant to the prosecution's case. An opinion occasionally suggested, is to present the evidence and let the jury decide. It is argued, a jury without the extensive understanding required to examine all aspects of an issue is not qualified to make a determination on some issues. Prior to a jury weighing the value of the evidence in a novel scientific technique, a test of acceptability can be legally required. This test of admissibility is known as a Frye test. Olsen explains the Frye test as:
The author of the article in review was apparently misinformed as to the issues considered during the appeal. According to the Court of Appeals Certified Opinion, there was only a single issue considered during the appeal. "Although defendant attacks the issue from several angles, the sole issue presented by defendant on this appeal is whether the trial court erred in instructing the jury with the standard form of CALJIC No. 8.40 (4th ed. 1986 pocket pt.)2/ defining voluntary manslaughter" [12]. Conceptually, what the author was attempting to accomplish is worthwhile. Unfortunately, the guidance he
followed and the approach he utilized lacked a thorough consideration of all the recognized factors for a complete and
integrated study. Any examiner considering similar experiments should be cautioned to consider all relevant factors,
follow scientific protocols, and limit conclusions to the extent supported by the study. The scientific certainty and
acceptability must be gained within the field of Friction Ridge Skin Identification prior to presenting testimony
in a court of law.
Alan McRoberts
Editor's Note: The decision to publish Mr. Schwabenland's case report was based upon reviewing the material as an accurate accounting of the events which occurred in the investigation, prosecution, and adjudication of a crime. A case report is, by definition, a brief description of an unusual case. The reported acceptance of Mr. Schwabenland's experiment by the court as meeting judicial requirements for expert testimony in this case was an important factor in providing this accounting. The material was not evaluated as to Mr. Schwabenland's experiment meeting the requirements of scientific validity, although the factors mentioned in the preceding special review have considerable merit. Readers as well as courts are always at liberty to agree or disagree with the methods described in a case report. Such is the nature of forensics when science is applied to the proceedings of law. However, Mr. Schwabenland's final statement in the case report is as follows:
Copies of transcripts of Mr. Schwabenland's testimony at the Superior Court trial furnished to the Editor by Mr. McRoberts and Mr. Kuhn have been reviewed. The experiment is not mentioned. A copy of the Fifth District Court of Appeals decision has been reviewed. The experiment of Mr. Schwabenland was not cited.
This special review was printed in Journal of Forensic Identification |