The following are some quotes from an article that I thought might be of some interest to those persons that follow this forum. The article is titled “Facial mapping, body mapping and the duties of an expert witness” and was presented at the ‘Public Defenders Annual Criminal Law Conference on the 3rd and 4th of March 2007. The author of the paper is Maciej Henneberg who is the Wood Jones Professor of Anatomy, University of Adelaide and the President-Elect of the American Dermatoglyphic Association. An association that one of the founding members was Prof. Harold Cummins. The empasis added to some words or phrases are mine.
Humans are variable in their body size, shape and function. Each individual is unique, and even two identical twins can be told apart by a number of slight differences in their external anatomy.
Prior to the widespread use of DNA in paternity cases, decisions whether a particular man was a biological father of a particular child was based on thorough comparison of over 200 characteristics of external anatomy and fingerprints of the child, the mother and the man who was a probable father.
Besides obvious dermatoglyphes on the palmar (under) side of fingers and palms, the exact shape of fingernails, shapes and proportions of fingers and palms are individually variable. The flexion creases around small joints of the digits form by the interaction of underlying anatomy and habitual use of hands and thus become unique identifiers.
In cases of legal identifications, be it for purposes of civil, or of criminal law, it is crucial that transparent, objective, and repeatable methods are used as these can be subject to cross-examination.
A trained biological anthropologist looks at images of humans with the background knowledge of the full range of human variation and with a systematic analytical approach.
The term “mapping” is used by some experts to give a semblance of a systematic, objective approach to identification from images. An expert witness inspects images and tries to describe the configuration of each anatomical detail, separately producing a “map” of the body or its part. Images of the person of interest should be inspected and described first, and the images of the known person, a “suspect”, only after the other set of images is fully described. This prevents subconscious reading of details of the ‘suspect” into the images to be identified. Usually “suspect” images are of higher quality than those to be identified, and thus “suspect” images contain detail invisible on other images. This detail may subconsciously influence the observer while examining images from a crime scene.
Some individuals have very average, common anatomical features, which render them similar to many other individuals, while some other people have rare anatomical variants, or specific malformations which make them unique at the first glance. The simplest example is the presence of scars, broken nose or loss of a finger. It is also important to note that even if each separate anatomical trait of a given person is fairly common, their combination may be rare.
The role of an expert witness, unlike that of other witnesses, is not only to describe facts, but also to provide an opinion which the court of law may treat as evidence (Plueckhahn and Cordner 1991). In inquisitorial legal systems expert witnesses are called by the court, while in adversarial systems they are called by the parties. It should be remembered however, that in any legal system the role of an expert witness is to provide the court with an objective description of facts and an unbiased opinion.
Despite the public image of exactness and precision, natural sciences rely on theories that are but approximations of the actual state of affairs, and in the process of research and debate these theories are subject to modifications. In scientific practice greater objectivity is achieved by the process of peer review. In its simplest form it consists of a review of results and conclusions arrived at by one scientist by his/her colleagues. In its most complex forms it involves extensive public debates in print, at conferences and in the media. The evolution of living organisms is just one example of vigorous debate that continues for over two centuries. Despite its pitfalls (Henneberg 1996, 1997) the process of peer review produces greater reliability of results of scientific work than the opinion of a single expert, however good.
In order to make the expert anatomist’s evidence more reliable it is necessary to minimize possible biases. This can be achieved in three ways:
(1) by ensuring that the expert is given only information relevant to the expert’s role in the case, because any “extraneous” information may produce biases of judgment
(2) by ensuring the independence of the expert from arguments of the parties; ideally by calling an expert by the court, practically by establishing a system in which an expert’s rewards and reputation are independent of providing evidence for or against a particular party
(3) by assessing the reliability of the expert’s statements and opinions through a peer review process - ideally by calling a second independent expert in each case; practically, by requiring experts to subject their opinions to the scrutiny of colleagues before they are presented to the parties and the court.
As with any activity involving human opinions, it is impossible to achieve an absolute objectivity of results of an anatomical identification, but strict adherence to good scientific practice and legal procedures, (eg Federal Court of Australia. 1998, Supreme Court of South Australia. SCR 38.01 A. 2002 ) together with ongoing research into human biological variation can ensure the usefulness of an anatomist’s expertise in legal matters.
A trained friction ridge analyst looks at images of friction skin with the background knowledge of the growth, persistence and uniqness of friction ridge variation and with a systematic analytical approach.