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Scientific Evidence (The following article was originally published in the Jan./Feb. 1983 issue of the defense attorney publication “Forum”. ) by HOWARD A. SPEAKS An expert, by definition, is a person who is very skillful or highly trained in some special field. There is no requirement that an expert know everything in the field of expertise. The fingerprint expert is in a field where knowledge and skill do not come quickly. The expert who can answer complex questions without assistance is a person with a great deal of experience in the field of expertise; his knowledge will certainly surpass that of either the prosecutor or defense attorney. Qualification Phase The qualification phase for the fingerprint expert is equally important to the defense attorney and the prosecutor. The verdict may hinge upon the acceptance of the fingerprint expert's evidence. It must be apparent to the trier of fact that the witness is an expert in the field of fingerprint identification and qualified to make fingerprint decisions. The prosecutor should ask the following questions: 1. What is your occupation? 2. How long have you been so employed? 3. What training have you had in the field of fingerprint identification? 4. Have you previously been qualified as a fingerprint expert? 5. State briefly the approximate number of times and in what courts. 6. What is a fingerprint identification? After these six questions have been answered, the witness should be offered to the court as an expert. It is important that the judge as well as the defense attorney audibly accept or reject the witness. Stipulation vs voir dire The prudent defense attorney must decide whether or not to take the witness on voir dire. If the training time of the witness seems very short, voir dire may be effective. If the answers seem to indicate a weak witness, there is nothing to lose by stipulation to the expert's qualifications. On the other hand, it is sometimes beneficial to stipulate rather than have a judge or jury hear the excellent qualifications of the witness. Stipulation by the defense at preliminary hearing is especially advantageous when the case is submitted on the transcript at the Superior Court level. Stipulation to fingerprint testimony should be in written form and should be approved by the expert. An improper stipulation can be damaging to the defense as well as the prosecution. Many times stipulations are made in an effort to save time, yet testimony by a qualified fingerprint expert should not take much more time than a stipulation. After a preliminary hearing it might be wise to engage, or ask the court to appoint, a private expert to review the fingerprint evidence and offer an opinion. Although not common, there have been cases where false fingerprint testimony has been offered. The life of a print The fingerprint witness is often asked to determine the age of a latent print. The expert witness knows that this is not possible. Many factors determine the life a latent fingerprint. The physical makeup of the print itself is most important. Latent fingerprints which are the result of the natural fluid coming from the fingers may, depending on the temperature, evaporate and disappear very quickly. In contrast, fingers which have come into contact with the body's sebaceous or oily secretions--—by running the fingers through the hair or touching the nose, for instance--—will almost always leave a good, long--lasting print. The surface where the print is found will also have an effect on the life of the print. So will the location. A print left in a cool shaded area will last much longer than one left in an unprotected sunny spot. Even prints left on good surfaces are often of no value after a relatively short exposure to ocean air. A neophyte fingerprint witness may refer to a “fresh” print. What he should have said was, “The print readily took the fingerprint powder.” There is no way to know if the print was fresh or if it was caused by the fingers having come into contact with sebaceous secretions. The qualified fingerprint witness will never make a statement regarding the life of a latent fingerprint. Positive Identification In 1970, the International Association of Identification appointed a standardization committee to conduct a three--year study to determine the minimum number of characteristics necessary to establish a positive identification. The study could find no valid basis for requiring a predetermined minimum number of friction ridge characteristics to establish a positive identification. Under the rules of evidence, anyone who qualifies in court as a fingerprint expert may testify as to his opinion regarding a comparison of two prints. The clarity of a latent fingerprint as well as the size of the latent lift is always considered when making a comparison. Latent fingerprints which are in an area of ridges where no pattern area is present are often very difficult to compare, but they pose no problem for the expert other than the extra time required. A positive identification is made when the expert finds the same characteristics in both the latent print and the inked exemplar prints. The characteristics must be in the same relative position on each print with the same number of intervening ridges. Minute differences caused by variances in pressure when the print was formed, pose no problem for the comparison of two fingerprints. Any difference in the two prints that cannot be explained as distortion will make it impossible to arrive at a positive identification. Types of characteristics There is a difference of opinion as to how many types of characteristics should be used when comparing fingerprints. This writer believes there are three different basic characteristics: 1. Bifurcation: the splitting of one ridge into two or more branches. 2. Ending ridge: the ending of a ridge.
3. Dot: a round black ridge with no length or sides. A fingerprint witness might refer to a trifurcation, which would be a bifurcation which had more than two branches. A spur is just a bifurcation with one leg that continues on. The court exhibit A well marked fingerprint exhibit will have a very damaging effect on the defense in any case. Usually the defense attorney has little time to examine the exhibit before it is taken to the witness stand for testimony. In that very short time the defense attorney must look for the following: 1. Is the exhibit neat? 2. Does anything in the exhibit seem confusing?
3. Are the marginal lines numbered or lettered? Lettered lines are an indication that the fingerprint witness will not refer to a number of characteristics. It is never wise for the defense to ask “Is this all you found?” A good clear latent print will result in the expert charting less than half of the characteristics present in the latent. The fingerprint expert should have no trouble explaining any of the characteristics he has charted. The prudent prosecutor will arrange to meet the fingerprint expert prior to court time and go over the exhibit. The fingerprint expert did not make the identification from the enlarged prints. The enlargements were made for the benefit of the jury. All fingerprint comparisons are made from the actual lift and an inked exemplar. Identification and classification Identification and classification are the two most misused words in the identification field. Identification tells who the person is and classification tells where, in the fingerprint file, we can find his card. Five percent of all fingerprints are in the arch family and will be either plain or tented. Thirty percent of all prints are in the whorl family, of which there are four members. The remaining sixty--five percent of fingerprints are in the loop family. This means that the great majority of fingerprints have classifications which are very similar. Classification refers to all 10 fingerprints while identification can refer to only a very small portion of one print. A fingerprint expert, rather than sound evasive, may ask an examiner if he is referring to identification or classification. It is certainly proper to ask questions regarding pattern interpretation in the qualification phase of a fingerprint witness; if the witness is a qualified fingerprint expert he should have a practical knowledge of classification. A more practical line of questions would address how a comparison is made. Impartial witness The fingerprint examiner is probably the most impartial witness to come before the court. In many cases the expert has never seen the defendant. The fingerprint witness has nothing to gain or lose from the outcome of a trial. Fingerprint testimony is never given in terms of approximation; fingerprint identification is an exact science. The fingerprint examiner will look at two prints and he will either see the exact same characteristics in both prints or he will not make an identification. The fingerprint expert is a highly respected member of law enforcement and can be proud to be part of a relatively small group of experts that have a nearly unblemished record for honesty. (Editor--— This article was written by long time SCAFO member and retired Los Angeles Sheriff's Department Latent Print Deputy Howard Speaks. He has nearly 50 years of fingerprint experience, with over twenty years doing private and defense work since his retirement from the Sheriff's Department in 1975. Howard has written numerous articles which appeared in Fingerprint Identification Magazine and publications like Forum where this article first appeared sixteen years ago. He has been a Fingerprint instructor at a local community college for nearly three decades and has provided basic and advanced fingerprint instruction to countless numbers of fingerprint personnel currently working, and many now retired. His literary efforts continue as valued contributions to our field. And through current discussions with this student, and I'm sure others elsewhere, continues to make his knowledge and love for the science known.)
This article was reprinted in “THE PRINT” |