U.S. v. Sanchez, 65 M.J. 145

Military Justice Personnel: Military Judge: Duties and Responsibilities

1. with respect to expert testimony offered pursuant to MRE 702, the military judge has a gatekeeping role; as gatekeeper, the judge is tasked with ensuring that an expert’s testimony both rests on a reliable foundation and is relevant
2. four factors that a judge may use to determine the reliability of expert testimony are: (1) whether a theory or technique can be or has been tested; (2) whether the theory or technique has been subjected to peer review and publication; (3) the known or potential rate of error in using a particular scientific technique and the standards controlling the technique’s operation; and (4) whether the theory or technique has been generally accepted in the particular scientific field
3. the test for determining the reliability of expert testimony is flexible, and the four factors that a judge may use to determine reliability do not constitute a definitive checklist or test; the focus is on the objective of the gatekeeping requirement, which is to ensure that the expert, whether basing testimony upon professional studies or personal experience, employs in the courtroom the same level of intellectual rigor that characterizes the practice of an expert in the relevant field
4. the military judge’s inquiry into the reliability of expert testimony is a flexible one, and the gatekeeping inquiry must be tied to the facts of a particular case; the trial judge must have considerable leeway in deciding in a particular case how to go about determining whether particular expert testimony is reliable; consequently, the trial judge has the same kind of latitude in deciding how to test an expert’s reliability as it enjoys when it decides whether that expert’s relevant testimony is reliable
5. the focus of the military judge’s inquiry into the reliability of expert testimony is on the principles and methodology employed by the expert, without regard to the conclusions reached thereby
6. under MRE 702, the military judge is required at a minimum to determine whether the expert witness’s conclusion could reliably follow from the facts known to the expert and the methodology used, mindful that conclusions and methodology are not entirely distinct from one another; trained experts commonly extrapolate from existing data; whether attempting to determine if there is too great an analytical gap between the data and the opinion proffered, or whether the proffered testimony falls outside the range where experts might reasonably differ, the goal is to ensure that expert testimony or evidence admitted is relevant and reliable, as well as to shield the panel from junk science
7. nothing requires that a military judge either exclude or admit expert testimony because it is based in part on an interpretation of facts for which there is no known error rate or where experts in the field differ in whether to give, and if so how much, weight to a particular fact in deriving an opinion; such a bright-line requirement would be at odds with liberal admissibility standards of the federal and military rules; the adversary system, including vigorous cross-examination, presentation of contrary evidence, and careful instruction on the burden of proof are the traditional and appropriate means of attacking shaky but admissible expert evidence

Core Criminal Law Subjects: Evidence: Expert / Scientific Testimony

1. MRE 702 dictates the admissibility of expert testimony; the rule permits expert testimony in the form of an opinion or otherwise only if the testimony: (1) is based upon sufficient facts or data, (2) is the product of reliable principles and methods, and (3) the principles and methods have been applied reliably to the facts of the case; the requirement that a scientific theory be generally accepted in the scientific community has been rejected, and the trial court has a gatekeeping role
2. with respect to expert testimony offered pursuant to MRE 702, the military judge has a gatekeeping role; as gatekeeper, the judge is tasked with ensuring that an expert’s testimony both rests on a reliable foundation and is relevant
3. four factors that a judge may use to determine the reliability of expert testimony are: (1) whether a theory or technique can be or has been tested; (2) whether the theory or technique has been subjected to peer review and publication; (3) the known or potential rate of error in using a particular scientific technique and the standards controlling the technique’s operation; and (4) whether the theory or technique has been generally accepted in the particular scientific field
4. the test for determining the reliability of expert testimony is flexible, and the four factors that a judge may use to determine reliability do not constitute a definitive checklist or test; the focus is on the objective of the gatekeeping requirement, which is to ensure that the expert, whether basing testimony upon professional studies or personal experience, employs in the courtroom the same level of intellectual rigor that characterizes the practice of an expert in the relevant field
5. the military judge’s inquiry into the reliability of expert testimony is a flexible one, and the gatekeeping inquiry must be tied to the facts of a particular case; the trial judge must have considerable leeway in deciding in a particular case how to go about determining whether particular expert testimony is reliable; consequently, the trial judge has the same kind of latitude in deciding how to test an expert’s reliability as it enjoys when it decides whether that expert’s relevant testimony is reliable
6. the focus of the military judge’s inquiry into the reliability of expert testimony is on the principles and methodology employed by the expert, without regard to the conclusions reached thereby
7. under MRE 702, the military judge is required at a minimum to determine whether the expert witness’s conclusion could reliably follow from the facts known to the expert and the methodology used, mindful that conclusions and methodology are not entirely distinct from one another; trained experts commonly extrapolate from existing data; whether attempting to determine if there is too great an analytical gap between the data and the opinion proffered, or whether the proffered testimony falls outside the range where experts might reasonably differ, the goal is to ensure that expert testimony or evidence admitted is relevant and reliable, as well as to shield the panel from junk science
8. the testimony of a pediatric physician that the physical examination of an alleged child sexual assault victim revealed a thickened hymen, a high vaginal white blood cell count, and anal dilation and that the constellation of her findings were concerning for sexual abuse, had a sufficient factual basis and was sufficiently reliable as to be admissible under MRE 702 governing the admissibility of expert testimony; as such, the military judge did not abuse her discretion in admitting this testimony and the ruling was not manifestly erroneous
9. nothing requires that a military judge either exclude or admit expert testimony because it is based in part on an interpretation of facts for which there is no known error rate or where experts in the field differ in whether to give, and if so how much, weight to a particular fact in deriving an opinion; such a bright-line requirement would be at odds with liberal admissibility standards of the federal and military rules; the adversary system, including vigorous cross-examination, presentation of contrary evidence, and careful instruction on the burden of proof are the traditional and appropriate means of attacking shaky but admissible expert evidence

Core Criminal Law Subjects: Evidence: Sexual Assault and Child Molestation

1. the testimony of a pediatric physician that the physical examination of an alleged child sexual assault victim revealed a thickened hymen, a high vaginal white blood cell count, and anal dilation and that the constellation of her findings were concerning for sexual abuse, had a sufficient factual basis and was sufficiently reliable as to be admissible under MRE 702 governing the admissibility of expert testimony; as such, the military judge did not abuse her discretion in admitting this testimony and the ruling was not manifestly erroneous

Trial Stages: Appeals: Standards of Review, Burdens, etc.

1. an appellate court reviews a military judge’s decision to admit or exclude expert testimony over defense objection for an abuse of discretion
2. when judicial action is taken in a discretionary matter, such action cannot be set aside by a reviewing court unless it has a definite and firm conviction that the court below committed a clear error of judgment in the conclusion it reached upon a weighing of the relevant factors; furthermore, the abuse of discretion standard of review recognizes that a judge has a range of choices and will not be reversed so long as the decision remains within that range; as long as a military judge properly follows the appropriate legal framework, a reviewing court will not overturn a ruling for an abuse of discretion unless it was manifestly erroneous; this standard applies as much to the trial court’s decisions about how to determine reliability as to its ultimate conclusion