A newer version of the platform is available. Please refresh the page.
Sign Up to Get information about Sales & Events Click Here
A newer version of the platform is available. Please refresh the page.
Posted by permission of Dr. Thomas O’Connor. Copyright by T. O’Connor.
“Doctors in all ages have always made fortunes killing their patients by means of cures.”R.D. Laing
The scope of expert testimony is infinite andincludes any relevant subject, so long as there are “experts” willingto venture an opinion distinctly related to a generally accepted science,profession, business, or occupation beyond the experience of the layman. Courtshave broad discretion in whom they will accept as an expert witness. Anybody canbecome an “expert” if they can establish, to the satisfaction of ajudge, that they possess some particular experience, training, education,or combination thereof that will aid the court in arriving at the truth on someparticular matter. However, depending upon the subject matter or expertise,there are specific rules and procedures for establishing the foundation, competency,and weight of the expert testimony. For the most part, juries are mostlyallowed to accept or ignore the expert’s testimony, but not always.
In providing their impartial, objectiveservices, experts only offer a sense of reasonable scientific certainty, notabsolute certainty. When two experts of unquestionable integrity disagree, it’sthe one who appears more impartial and objective that is given more credence bythe court. In other cases, it’s more appropriate to compel or make use of acourt-appointed expert witness. Such compelled experts, under subpoena ducestecum (bring all documents), must usually be paid a fee, as well as anothertype of expert, called a meta-expert, who under amicus curiae (friend of thecourt), files a brief trying to resolve complex scientific issues or responds ata distance to hypothetical questions. Yet another type of expert, theexpert-advisor (not really a witness), assists one side of the case in juryselection and cross-examination strategies.
Experts are expected to be advocates of thetruth, equal advocates of the prosecution or defense. However, defense expertsare usually paid a fee or have their expenses picked up. They work on afree-lance, case-by-case basis. Prosecution experts are usually employees of thestate, and if “forensic science” is somewhere in their jobdescription, they are expected to always be “on call” to testifywithout any extra compensation (with few exceptions). Although the prosecutionhas the advantage of a ready-made pool of experts, the risks are greater sinceif any government employee expert is discredited or impeached since the taintgoes all the way back to the lab, agency, or department they represent. OK, torecap the different TYPES of experts:
Experts are usually paid very well. Some experts have received several hundred thousand dollars for work on a single case. Forensic psychology (which is often the initial field of entry for most experts) usually pays around $250 or $350 per hour, and other experts are paid even more. In a related field called appraisal, appraisers not only make something like these amounts per hour, but also receive a percentage of the value of any object they appraise. In some fields, however (like forensic social work), the generally accepted standard is that an (ethical and professional) expert would charge no more than what they are paid for the services they do in their regular job. Experts who don’t have regular jobs represent a status making up the definition for the following phrase — “whores of the court” — a phrase and phenomenon most closely explored by Margaret Hagen (1997) in her book so titled, where the following excerpts are illustrative:
The “Whores of the Court” Conceptualization
“Thousands of psychological “experts” confidently and expensively inform judges and juries, patients, plaintiffs and defendants not only about how memory works but how the mind itself works, how the personality is formed, what aspects of character and behavior can be changed and how to go about it, as well as what wrong was done, when and how it was done, who did it, how much responsibility a party bears, and whether and when said party can be rehabilitated. In the civil realm, psychexperts determine for the courts the nature and extent of psychic injury, disability, and discrimination, the presence of abuse, and the relative fitness of parents.”
“The demand is great, the supply is huge, and the science behind it all is nonexistent. But the reality does not matter.”
(Source: Hagen’s Chapter 1: Psychologists as De Facto Triers of Fact in Our Justice System)
Experts are usually asked during cross-examination how much they are being paid for their testimony, and if the amount is perceived as exhorbitant, the credibility of the information being provided may be called into question. Some experts witnesses have found it difficult to collect the fees they were promised, especially if the outcome of the case was unfavorable or the expert’s testimony was called into question for any reason.
A SELECT LIST OF AREAS FOR EXPERT PRACTICE
ALCOHOL INTOXICATION – Some courts allow police officers, specially trained in a National Safety Council approvedcourse, to testify as to impairment on the standards of .05 (judgment), .08 (coordination), and .10 (reflexes),based on breathalyzer-type instruments, various field sobriety tests, and Horizontal Gaze Nystagmuswhich measures theinability of the eyes (involuntary jerking) to maintain visual fixation as they are turned to the side.
AUTOMOBILE AND AIRPLANE CRASHES – Some courts allow patrolmen with extensive experience in accident investigationand refresher course qualification to testify as to speed, point of impact, and other non-ultimate issues. Airplaneexpertise usually requires an engineering degree and experience. It is common for this kind of expert todemonstrate exhibits showing reconstruction of the accident.
BALLISTICS – The science of forensic ballistics is well-established but frequently challenged. Most courtswill allow testimony showing that the bullet which killed a person was fired from a weapon belonging to a defendant.Likewise, testimony as to breechface and/or firing-pin markings, striation patterns, and gunpowder residue is commonlyaccepted. Glass and wound pattern analysis has yet to gain widespread acceptance. Courtroom demonstrations areusually prohibited, so laboratory results are often substituted, with this opening the door to whether the labis comparable to the FBI’s lab or another major laboratory. There are a varietyof different ballistic techniques, but they all usually have to do with scienceof motion for projectiles.
BITE MARK ANALYSIS – Normally would require credentials in forensic dentistry, and special training in theABFO (American Board of Forensic Odontology) scale and other pathologist skills, such as saliva extraction. Thisfield took a hit about a decade ago when an association discredited a famous expert for his special blue lightingtechnique and interpretation methods. A highly controversial field, even for forensic dentists.
BLOOD GROUPING TESTS AND BLOOD SPATTER ANALYSIS – Some courts are allowing competent analysts (other thanserologists) to admit results of field tests on blood samples, especially when it comes to determining secretors.Normally, a serologist can admit more refined tests without much challenge. Spatter (which should be spelled splatter)analysis is part of the detective craft. Based on the laws of physics, the tail of a blood drop always points tothe origin, the size estimates height, and shape determines angle of impact. When admitted, usually accompaniedby an exhibit explaining the principles. Courts have wide latitude in this area.
DNA (Deoxyribonucleic Acid) TESTS – There have been significant breakthroughs, but it is also one of themost fiercely challenged areas. DNA “fingerprinting” is generally considered reliable, but challengescontinue to occur at the laboratory protocol (contamination) level and the extent of interpretation (how much isleft to the jury).
DOCUMENT EXAMINATION – A growing area of fraud and white-collar crime investigation.With white-collar crime, requires almost theequivalent of a degree in accounting but is readily attainable thru certification programs.Questioned document examination ascertains the authenticity or source ofhandwriting or typewriting. Graphology is handwriting analysis. Other expertsare involved in the analysis of paper and ink, obliterations, and erasures. Someinsurance fraud and arson investigators have a specialty with burned or charreddocuments.
DRUG COURIER PROFILING AND PROFILING IN GENERAL – Some courts are allowing specially trained police officers(especially DEA agents) an expertise in identifying movements of a drug dealer (or other criminal), the meaningof “drug (or gang) lingo”, paraphernalia, the significance of phone traffic and other behaviors.John (solicitation of prostitution) profiling has also received court approval.Serial killer profiling is a highlycontroversial area in search of a scientific method. So-called racial profilingis about traffic stops, and has little to do with science at all.
EYEWITNESS IDENTIFICATION – Usually a social psychologist who augments or impeaches the witness’ cognitiveor perceptual abilities at a showup, lineup, or recollection of facts. Memory experts tend to bring a lot of booksto the courtroom, and Perception experts tend to host simple courtroom demonstrations. Both tend to talk the languageof misperception: assimilation/contrast effects, sociodemographic bias, lighting, figure/ground gestalt, etc.
FINGERPRINT IDENTIFICATION – Very well-established area where an average officertestifies they obtained a setof latent prints from the crime scene, but to connect them with a known suspectusually requires an AFIS-certified expert. Usually suchexperts are available or in training at state or regional crime labs and policedepartments. Under some circumstances, the courts willallow average officers to testify. Usually, enlarged photographs or other exhibitsdemonstrate the points ofcomparison upon which the conclusion was reached. In a crime lab, thefingerprint unit is called the Latent Fingerprint Unit and processes latentprints that come in from police departments.
FIREARMS IDENTIFICATION – This can refer to the work of a crime lab unitor a free-lance gun expert who is capable of examining cartridge cases, shells,and ammunition of all types. Garments and other objects are also sometimesexamined in terms of discharge residue. Firearms identifiers rely upon some ofthe same principles as tool mark experts.
FORENSIC ANTHROPOLOGY – An area involved in such things as time of death, age, race, and sexof victim, and reconstruction of facial appearance from skeletal remains. The areamight also involve counting the sizeof the largest maggot to give an estimate of the time of death. Often, a high-tech field using computerreconstruction of the skin around skeletal remains or age-progression on missingpersons. Another related specialty area involves helping identify victims ofmass disasters, like plane crashes.
FORENSIC BIOLOGY – This most commonly describes biologists and serologistswho work in a crime lab who identify and type dried bloodstains, other bodyfluids, and DNA. Others work with hairs and fibers as well as identify andcompare botanical specimens such as wood and plants.
FORENSIC ENGINEERING – A broad field most often involving the study ofaccident scenes, structural failure analysis, and sometimes explosions or fires.The expertise quite usually consists of opinion on the ultimate issue, that is,which party was responsible and/or negligent.
FORENSIC ENTOMOLOGY – The study of insects and their relation to acriminal investigation, such as the analysis of larvae and maggots, but alsosometimes involving a particular knowledge of insects, their habitats, lifecycles, and habits.
FORENSIC ODONTOLOGY – Also called forensic dentistry, this is the study ofthe hardest substance in the human body, teeth enamel. With the use of dentalrecords, X-rays, casts, or even a photograph of a person’s smile, experts canoften make identifications and comparisons. A related subspecialty is bite markanalysis.
FORENSIC PATHOLOGY – A title for some extra-qualified county coroners or medical examiners who work closelywith police but “own” the body at the crime scene. Numerous techniques used here, depending upon financialresources of a community, but still based around the autopsy. The expertiseinvolves the medico-legal investigation of sudden, unnatural, unexplained, orviolent deaths.
FORENSIC PHYSICAL SCIENCE – This most commonly describes the servicesprovided by a physical science unit of a crime laboratory where the techniquesof chemistry, physics, and geology are brought to bear on the identification ofcrime scene evidence. Such personnel are usually called criminalists and performa variety of tests as well as use analytical instruments on trace evidence suchas soil, paint, and glass.
FORENSIC PSYCHIATRY – A broad term for a diverse field that coverseverything from evaluations of competency to stand trial, insanity, andparticular relationships between certain psychological conditions and humanbehaviors.
HAIR AND FIBER ANALYSIS – Generally relies upon laboratory devices involving the techniques of Spectrography(absorption of light by a substance) and Chromotography (the chemical reactions of a substance) to produce findingssuch as what you had to eat three years ago (in hair samples). Fiber analysis tends to use the simple means of10x microscopes (or higher).
HANDWRITING COMPARISON – Usually requires some special training and experience in handwriting analysis, andin addition, a familiarity with the handwriting of the individual in question. Most courts allow the expert “ahigh level of belief” rather than absolute certainty, and a sample size of 10 points of comparison is becomingstandard.
HYPNOSIS – Generally not acceptable in most courts of law, and frequently challenged even if used for victimmemory refreshment where it is allowed. An interesting field based on some of the same principles as interrogationin police work.
MICROTRACE ANALYSIS – The phrase used to describe a variety of techniques all involving study of a specimenunder a microscope. Evidence is collected using a micro-vacuum like the kind that clean computer keyboard keys.The expertise is called forensic physical science, general forensic science,evidence collection, or criminalistics.
NEUTRON ACTIVATION ANALYSIS – Some courts are allowing this, which is a fancy name for swabbing a nitricacid solution over the webbed portion of a person’s hand to see if the residual levels of antimony and barium aretypical of a person who has recently fired a gun. Holds the promise of detecting other things over a longer timeperiod.
PHOTOGRAPHY – Police photography is fast becoming an expert area, now with infrared and other high-tech devices.Part of the detective craft has always been to tell a story about the crime using pictures, and crime scene photographyhas always had its own standards over and above what the court requires. Digital photography needs to have similarstandards because photographs can be easily retouched by computers. Amateurphotography experts (who know their filters and lenses) are sometimes used bythe courts in some specialized matters, and photography laboratories often makeuse of specialized techniques, such as infrared, ultraviolet, and X-ray. If aphotography unit exists in a crime lab, this unit usually helps preparecourtroom exhibits.
PHYSICAL AND MENTAL CONDITION – Experts in this area are usually medical doctors or psychiatrists, but itis not usually necessary to be a licensed medical practitioner. Researchers, optometrists, toxicologists, or evenmedical technicians have been allowed to testify with the exception that psychiatric testimony must be given bya psychiatrist, not a psychologist. Even clinical psychologists are prohibited from testifying in most jurisdictions.Courts have wide latitude in deciding whether testimony going to the defendant’s mental state (such as the abilityto form intent) is admissible.
POLYGRAPH EXAMINATION – Generally not acceptable in most courts of law because of unreliability and a lackof recognized training programs. However, may be admitted if both parties (defense and prosecution) consent, butany arrangements (or results) are non-binding for the defense. An alternative to the polygraph, called the PsychologicalStress Evaluator, has come out in recent years, but it also has yet to gain acceptance.The polygraph is better thought of as a tool for the investigator and not theforensic scientist.
SKETCH ARTIST – The area of forensic art has remained in a state of infancy, but has included such crafttechniques as suspect composites and crime scene sketching. The trend is to use computer software, mapping programs,and high-tech projection devices for courtroom use.
SOIL SAMPLE ANALYSIS – Usually requires education and experience with agricultural science, geology, and/orchemistry. Techniques such as the density gradience test (comparing two samples to within 50 feet of one another)are easily doable in any laboratory. More refined tests to exact a location unlike anywhere else on earch requiresa more sophisticated laboratory.
SPEED DETECTION READINGS – RADAR (Radio Detection and Ranging) devices have long been acceptable to the courtsbecause they are based on the well-established Doppler effect, and police departments have adequately demonstratedsufficient training and fine-tuning in their use. However, some courts have thrown out radar evidence when thepolice had no record of calibration tests on the LED circuitry and/or the tuning forks used in calibration. Inaddition, occasional defense attorney research turns up such things as cosine, batching, and shadowing errors whichinherently plague the use of these devices. VASCAR (Visual Average Speed Computer and Recorder) is a more mechanicalerror-free device involving the throwing of switches as a car passes between two fixed points, with the officerassisted in the dt = r x t formula. More recently, LASER guns have come into widespread usage, which can also pickupsounds behind panes of glass, but no known court case has judged on them yet.
TOOL MARK ANALYSIS – A detective craft involving casting impressions (marks left behind on a softer surface)and lifting imprints (marks left behind on hard surfaces). Also involves some specialized knowledge in the manufactureand use of hammers, pry bars, etc. Usually the cast or imprint is admitted into physical evidence with the witnesstestifying as to chain of custody rather than as an expert. Tool mark analystsrely upon some of the same principles as firearms identification experts.
TOXICOLOGY – Some courts allow expertise at the level of lab technician to qualify, but generallythis area requiresa degree in Chemistry or Medicine, often at the master’s level. Involves tests for poisons, narcotics, blood, or other bodily fluids.Often, a toxicology unit also has responsibility for drug and alcoholidentification as well as training others in alcohol intoxication testing.
TRUTH SERUM RESULTS – Also called Narcoanalysis, it is important to remember than confessions extracted underthe administration of drugs is constitutionally inadmissible. Some courts, however, have admitted interpretationsof statements if not the tests themselves by expert medical psychiatric witnesses. These situations usually involvea placebo (sodium amytal or sodium pentothal – which have no “truth telling” properties but cause someoneto speak more freely; as opposed to scopolamine – which does have a “truth telling” chemical effect).
TYPEWRITER COMPARISON – Long acceptable, the techniques of showing that a certain document came from a certaintypewriter have required little by way of qualification, although the FBI has a laboratory for this. In some cases,an expert can tell if a certain person typed the document based upon personal style characteristics in manner ofpunctuation, length of lines, depth of indentation, etc. More recently, computer and computer printer expertiseis a new development.
VOICE PRINT ANALYSIS – Spectrographic voice analysis has not gained the degree of general acceptanceto make it admissible in most courts mostly due to limited number of experts. In most cases, the jury is allowedto hear the samples themselves. It is most often used in cases involvingtelephoned threats or tape-recorded messages by investigators and not forensicscientists.
REFERENCES
Hagen, M. (1997). Whores of the Court: The Fraud of Psychiatric Testimony and the Rape of American Justice. NY: HarperCollins.
Inman, K. & Rudin, N. (2000). Principles and Practice of Criminalistics: The Profession of Forensic Science. Boca Raton, FL: CRC Press.
James, S. & Nordby, J. (Eds.) (2005). Forensic Science, 2e. Boca Raton, FL: CRC Press.
Jasanoff, S. (1997). Science at the Bar: Science and Technology in American Law. Cambridge, MA: Harvard Univ. Press.
Kiely, T. (2005). Forensic Evidence: Science & The Criminal Law, 2e. Boca Raton, FL: CRC Press.
Moenssens, A., J. Starrs, Henderson & Inbau. (1995). Scientific Evidence in Civil and Criminal Cases. Westbury, NY: Foundation Press.
Saferstein, R. (1998). Criminalistics: An Introduction to Forensic Science. NJ: Prentice-Hall.
Wecht, C. & Rago, J. (Eds.) (2005). Forensic Science and Law. Boca Raton, FL: CRC Press.