Substantive Admissibility of 3D Forensic Medical Graphics and Models

Kiaran P. McGee, Ph.D.
Jonathan M. Morris, M.D.
R. Ross Reichard, M.D.
Kevin P. O’Laughlin, J.D.
Chuck MacLean, J.D., Ph.D.

The full article is available to read in the recently released 44:1 issue of the American Journal of Trial Advocacy.


          Criminal trials should be searches for the truth.  Over time, as science has progressed, criminal trials have admitted as substantive evidence those scientific theories and techniques that are capable of being successfully tested, that are subjected to peer review and publication, that have a known or potential error rate, that follow recognized and well-maintained standards, and that are widely accepted in their scientific fields.  Many three-dimensional (3D) forensic medical radiographic techniques have arrived at the threshold for substantive admissibility in criminal trials.  After all, these radiographic techniques are routinely used around the world to drive critical diagnoses and treatments and to plan complex surgeries.  As such, they qualify as competent evidence to assist triers of fact in criminal trials.  Providing medical evidence in a 3D format helps the evidence cross the threshold of admissibility by improving the clarity and impact of medical evidence.  Once relegated to oral summary from the witness stand or two-dimensional (2D) imagery, medical evidence has historically been restricted to demonstrative evidence. 

          The added complexity and information provided by 3D medical evidence has the potential to be allowed to accompany jurors into the deliberation room.  Instead of limiting complex substantive evidence admitted in criminal trials to oral testimony or demonstrative evidence alone, several categories of 3D medical forensic evidence are today’s versions of yesterday’s photographs and x-rays.  Complex medical evidence, painstakingly offered through the oral testimony of physicians, forensic pathologists, and other qualified experts, may leave jurors and even some judges unable to fully grasp the meaning and import of that medical evidence.  It is time for the next generation of medical evidence to enjoy the same level of admissibility as photographs—and for the same reasons.  This brief Article considers the main variants of the current generation of 3D medical evidence, the reliability and validity of those variants, and how to overcome the main evidentiary challenges to admitting 3D medical evidence reconstructed from cross sectional CT and MRI imaging in criminal trials. We begin with a brief history of the radiologic and legal evolution that lead to the development of today’s 3D technologies.