Irresponsible Expert Testimony
Brian K. Holmgren, JD
Assistant District Attorney General, Davidson County, Tennessee.
Cases of shaken infant syndrome are increasingly being litigated in the juvenile and criminal court systems. This has resulted in a proliferation of expert witnesses being called to testify by both the prosecution and the defense. The issue of irresponsible expert testimony has justifiably received some attention in both the scientific literature and the popular press, especially in the wake of some highly publicized cases.
What is frequently not appreciated by both professionals in the field and by the public is the extent to which the legal system facilitates irresponsible expert testimony. Most people understand that our legal system is adversarial, and that each side in a legal dispute has the opportunity to present witnesses to support their respective positions in the courtroom. From this process jurors or judges, the fact finders, are supposed to be able to discern the truth, at least in theory. Most people also recognize that this system creates incentives for the parties to bring forward The truth is often lost in the battle of the competing experts. Jurors who decide these cases frequently confront the problem that "if the experts can't agree, how can we?" Consequently, there is an incentive for those defending against allegations of child abuse to throw up an expert on the other side - to create a controversy, whether one legitimately exists or not. Controversy inures to the defendant's benefit, given that the government bears the burden of proof regarding the allegations.
In criminal cases the defense is frequently attempting to create doubt along a broad spectrum of issues, what prosecutors frequently call the shotgun approach to reasonable doubt. Accordingly, the defense might attempt to suggest the child's injuries are not the result of abuse, or if they are the result of abuse the defendant is not the one who caused them. The defense expert will frequently suggest the medical findings result from a disease process such as meningitis, alagille syndrome, glutaric aciduria, or adverse reaction to DTP vaccinations. Or the expert might suggest an alternative medical cause for one or more of the key medical findings. For example, CPR or child birth caused the retinal hemorrhages, or the subdural hematoma or skull fracture was caused by an accidental fall or by being dropped from the caretakers arms. Some experts will attempt to expand the time frame for when the injury occurred so that other "caretakers" could be responsible. Still other experts will suggest the caretaker was not aware of the dangers of shaking the child and therefore lacked the requisite mental purpose or mens rea necessary for the crime alleged.
Even in juvenile cases these problems are pervasive. The juvenile court finding does not require proof of who caused the child's injuries. As long as the government proves the child was abused the allegations of the petition will be substantiated and the court will have jurisdiction over the child. Therefore, the burden for the defense is often to prove the medical findings are not the result of shaking, but instead the product of some other disease process or circumstance, e.g. the child's injuries are consistent with an accidental fall.
Legitimate controversy exists in some areas of the medical research and reasonable medical opinions may differ over select issues. Seldom do these controversies reach the core science of shaken infant syndrome or attack the legitimacy of the medical criteria used to diagnose this form of child abuse.
How Does the Legal System Facilitate Irresponsible Expert Testimony:
1. We set very low qualifications for expert witnesses. The law generally defines an expert as someone with specialized training, skill or knowledge who can assist the finder of fact in understanding an issue. Since prospective jurors who know anything about the subject matter of the case are generally excluded from the actual jury, we wind up with a jury which is not very knowledgeable about the subject at hand, and even less knowledgeable about the complex medical science involved. Accordingly, virtually any physician will have more knowledge than the average juror and hence be technically qualified to testify as an expert under the rules of evidence.
We couple this fact with a liberal presumption in favor of admissibility of expert testimony under the Federal Rules of Evidence. The relative qualifications of the expert go to the weight to be given to his or her testimony, but generally don't preclude the expert from giving an opinion. Often the experts qualifications are established in court on the basis of how often he or she has testified before. As doctors Chadwick and Krouse point out, however, "experience testifying" is not "expertise". If an experts true qualifications are not scrutinized on prior occasions in court, then a judge's erroneous qualification of an expert simply serves to perpetuate the mistake by permitting the expert to subsequently testify that "he has been qualified as an expert on x number of occasions in the past."
As Yale Law Professor Donald Elliot points out, "the law accords equal dignity to the opinions of charlatans and Nobel Prize winners." It is up to the skill of the attorney questioning the expert witness to expose the charlatan from the true expert.
2. The law makes Judges the "gatekeepers" for determining whether the expert's opinions should be admitted in court. Judges are supposed to make determinations on a case by case basis of whether the expert's opinion is reliable enough to be heard by the jurors. This necessitates that the judge and the attorneys questioning the expert become amateur scientists in order to be in a position to discern whether the witness is truly an expert offering reliable information. Lawyers became lawyers in large measure so they wouldn't have to learn "science." Given the complex nature of the medical science involved in SBS cases, and the time lawyers can devote to learn this material amidst their other duties, one appreciates that it is relatively easy for the irresponsible expert's opinions to slip by undetected. In making decisions on admissibility the law depends, to some extent, on the self-professed integrity of the expert's representations of what the science really says about the subject, a point which of course is antithetical to what the irresponsible expert is all about.
3. The law permits the expert's opinion and the basis for their opinions to remain hidden until they are presented before the jury. Prosecutors and government attorneys in juvenile court proceedings are generally required to provide extensive disclosure of the opinions of their experts prior to trial. This is frequently not the case for defense experts. Prosecutors quite often have limited knowledge about what the defense expert will say in court, and sometimes may not even know who the expert will be. Even if the prosecutor does know this information he frequently will not know what the defense expert is relying on as a basis for his opinions (e.g. personal experience, research data, and medical literature). Nor will the prosecutor know if other experts have been consulted by the defense who had opinions contrary to those of the expert being called.
The rules of evidence additionally permit the expert to come into court and offer their opinion (e.g. this child was not a victim of SBS), without the requirement that they state the basis for this opinion. This is left for the prosecutor potentially to delve into on cross-examination, creating a veritable Pandora's Box, which if opened may prove disastrous.
4. Judges are more likely to admit a defense expert than to exclude them. While judges exercise broad discretion in determining the admissibility of expert testimony, judges are much more likely to exercise that discretion to exclude a government expert than a defense expert. This results in part from a judicial philosophy that favors the rights of defendants to present a defense, and a concomitant fear by trial judges that if they exclude a proffered defense expert they may be reversed on appeal. The government seldom has a right to appeal an adverse ruling excluding their expert and appellate decisions frequently criticize trial courts for permitting too much latitude in the types of opinions expressed by prosecution experts. Appellate courts rarely suggest that defense experts have crossed the boundary lines. All of these factors contribute to a bias in favor of the admissibility of defense experts and to wider latitude being afforded to their opinions.
The right to present a defense, however, does not include the right to present irrelevant evidence. If an expert's testimony is unreliable, then it is also irrelevant and the trial court commits no error in excluding it.
5. The law permits medical experts in child abuse cases to offer opinions on the ultimate issue. In the context of child abuse or child homicide cases, this rule permits the expert to offer an opinion on whether the child was abused or not, how the injuries came about, what caused the child to die and whether the manner of death is a homicide or an accident. This rule of evidence is necessary and appropriate, and experts testifying on behalf of the government are also entitled to offer such opinions. Indeed, without such opinions it might be impossible to obtain a conviction. However, when the government offers its medical opinions touching on the ultimate issue it must satisfy a fairly high burden of proof of beyond a reasonable doubt or clear and convincing evidence. Conversely, the defense expert's opinion need only suggest a possibility that the injuries are non-abusive in order to create doubt in the case. Consequently, an irresponsible expert opinion dealing with an ultimate issue is more likely to adversely affect the outcome when offered by a defense expert than by a prosecution expert.
6. The expert is able to rely on inadmissible evidence, including hearsay, and need not have personal knowledge of the subject matter. The law provides that experts can rely on facts or data that need not be admissible in evidence, "if of a type reasonably relied upon by experts in the field in forming opinions or inferences upon the subject." However, the experts themselves define what they or other experts in the field would consider reliable. For some irresponsible experts this will include unchallenged hearsay, isolated clinical cases and anecdotal information from colleagues. Others will rely on poorly researched scientific articles that survive the peer review process without critical analysis or commentary.
Once again, the government's experts enjoy the same latitude in offering their opinions. However, those opinions are judged by higher standards. An expert is much less likely to go out on a limb in offering an opinion if that opinion and the foundation it rests on are held up to high standards of proof. By contrast, experts whose opinions are judged by a much lower standard of reliability can create doubt or controversy by merely offering the opinion. They don't have to back it up to the same degree for their words to have effect.
This problem is potentially exacerbated by several additional legal rules that facilitate the giving of irresponsible opinions.
First, medical opinions need not be stated to a reasonable degree of certainty in order to be offered in many jurisdictions.
Second, the rules of evidence permit the expert to base an opinion on inadmissible evidence, including hearsay. Some irresponsible experts frequently base their decisions in part on the self-serving denials of the accused, or accept an inadequate or implausible historical account as a basis upon which to form their opinions. In practice this may allow the irresponsible expert to base his opinions on the out of court denials of the defendant without the necessity for the defendant to testify and be cross-examined. While several cases suggest that such practice is not permitted, in reality it is often difficult if not impossible to pierce the veil surrounding the expert's opinion before it is offered. This occurs because the expert need not disclose the underlying basis for his opinion, and because even if the expert is aware of the impropriety of using the non-testifying defendant's statements as foundation they may still do so purposefully or subconsciously. In other circumstances, the defendant's out of court statements may be offered into evidence by the prosecution, thereby affording the defense expert the opportunity to offer an opinion that in his "less than critical judgment" it could have happened like the defendant says.
Third, the expert need not have personal knowledge of the subject he is offering testimony about. Consequently, a physician need not have personally examined the child in order to offer an opinion in court. Nor must the expert routinely see similarly situated children in daily practice in order to offer an opinion. This rule permits irresponsible experts who don't see abused children the opportunity to come to court and share their lack of expertise. It is also an open invitation for physicians who may have expertise in one area to step into a different arena where they don't have similar credentials and nevertheless provide their two-cents worth.
Fourth, one of the criteria for evaluating the admissibility of expert testimony is whether the subject matter the expert is offering an opinion on has been scientifically tested, subjected to peer review, and published. Unfortunately, the peer review process is not always a reliable barometer for poor scientific methodology and uncritical acceptance of journal articles through the peer review process operates to facilitate the perpetuation of poor science in the courtroom. Because prosecutors and judges lack medical expertise, they are poorly equipped to challenge this science in the exercise of their gate keeping function to scrutinize expert testimony.
Mr. Holmgren became an Assistant District Attorney General with the Davidson County District Attorney Generals Office in Nashville, Tennessee on August 9, 1999. Previously he served as an Assistant District Attorney in Kenosha County, Wisconsin for ten years where he directed their sensitive crimes unit. As an Assistant District Attorney in Wisconsin, Mr. Holmgren tried more than 160 jury trials including 125 felonies, and handled hundreds of child abuse cases. He currently serves on the National Center on Shaken Baby Syndrome International Advisory Board.
# See generally, David Chadwick & Henry F. Krous, Irresponsible Medical Testimony by Medical Experts in Cases Involving the Physical Abuse and Neglect of Children, 2(4) Child Maltreatment 313-321 (1997); David Chadwick et al., Shaken Baby Syndrome - A Forensic Pediatric Response, 101(2) Pediatrics 321-323 (1998); M. Higgins, Docking Doctors? AMA Eyes Discipline for Physicians Giving False Testimony, 84 American Bar Association Journal 20 (1998). For articles critiquing prosecution experts in some SBS cases see Jody Tabner Thayer, The Latest Evidence for Shaken Baby Syndrome - What Defense Lawyers and Prosecutors Need to Know, Criminal Justice, Summer 1997, pp. 14-22; Mark Hansen, Why Are Iowa's Babies Dying?, ABA Journal, August 1998, pp. 74-78.
# See, e.g., State v. Lopez, 412 S.E.2d 390 (S.C. 1991) and State v. McClary, 541 A.2d 96 (Conn. 1988), holding that SBS is a well accepted medical diagnosis which does not require a Frye test for admissibility. See also State v. Compton, 701 A.2d 468 (N.J. Super 1997), upholding reliability of expert testimony involving SBS. But see, Hansen, supra note 1, quoting several defense experts who suggest that SBS is frequently over diagnosed and misunderstood by other physicians who testify in court for the prosecution.
# Federal Rules of Evidence, Rule 702.
# Paul Stern, Preparing and Presenting Expert Testimony in Child Abuse Litigation: A Guide for Expert Witnesses and Attorneys, Thousand Oaks, CA: Sage (1997).
# State v. Schumpert, 435 S.E.2d 859 (S.C. 1993); Commonwealth v. Azar, 588 N.E.2d 1352 (Mass. Ct. App. 1992); State v. Dumlao, 491 A.2d 404 (Conn. App. 1985)
# See Chadwick & Krous, supra note 1.
# Federal Rules of Evidence, Rule 104(a); Daubert v. Merrell Dow Pharmaceuticals, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993); Kumho Tire Co. v. Carmichael, 119 S.Ct 1167 (1999).
# See Federal Rules of Evidence, Rule 705, which provides The expert may testify in terms of opinion or inference and give his reasons therefore without prior disclosure of the underlying facts or data, unless the court requires otherwise. The expert may in any event be required to disclose the underlying facts or data on cross-examination.
# See Margaret A. Berger, Procedural Paradigms for Applying the Daubert Test, 78 Minn. L. Rev. 1345, 1354-63 (1994), listing cases; State v. Cheeks, 852 P.2d 655 (Kan. 1993); McCartney v. State, 414 S.E. 2d 227 (Ga. 1992)
# Federal Rules of Evidence, Rule 704(a)
# Federal Rules of Evidence, Rule 703.
# An expert's opinion must rest on a reasonable degree of certainty. The greasonable certaintyhstandard sounds more impressive than it is. Few authorities provide meaningful insight into the degree of certainty required to express an opinion, or on how reasonable certainty is defined or assessed. Locating reasonable certainty somewhere between the poles of guesswork and complete certainty adds little to the concept, and, in the end, the reasonable certainty standard fails to provide a meaningful tool to evaluate expert testimony. A more productive approach looks beyond the rubric of reasonable certainty, and asks questions that shed light on the factual and logical strength of the expert testimony.
# "John E. B. Myers, Evidence in Child Abuse and Neglect Cases, 3d ed. p. 464 (1997). See also 3 Mueller & Kirkpatrick, Federal Evidence, 2d ed. p. 629-30 (1994), The fact that an expert cannot be categorical and admits of some uncertainty in his conclusions, does not mean that his testimony fails the helpfulness requirement. Lay witnesses routinely testify to their recollection of events while admitting uncertainty, and at least as much latitude extends to experts." 12 Rather, legal precedent indicates that medical opinions offered to a lesser standard of certainty are still admissible, with the jury being left to accord appropriate weight to such opinions.12...12.... State v. Warness, 893 P.2d 665 (Wash. App. 1995); State v. Sibert, 648 N.E.2d 861 (Ohio App. 1994); People v. Brown, 496 N.E.2d 663 (N.Y. App. 1986); People v. Jackson, 18 Cal. App. 3d 504, 95 Cal. Rptr. 919 (1971). Even in jurisdictions which require medical opinions to be stated to a reasonable degree of medical certainty,@ this standard is determined by the expert's own definition of what that term means. It should be obvious that an irresponsible expert's standard in this regard will be far less stringent than a responsible expert's.
# See, e.g., Clemens v. State, 610 N.E.2d 236 (Ind. 1993).