Biomechanist Dr. Andrew Rentschler is set to testify as the likely final defense expert witness in the trial of Karen Read, accused of the death of Boston police officer John O’Keefe. His testimony challenges the prosecution’s assertion that Read’s 2021 Lexus SUV struck O’Keefe in reverse during a severe blizzard on January 29, 2022, causing fatal injuries. Rentschler, part of the crash reconstruction firm ARCCA, is expected to testify for several hours on Wednesday before the defense rests its case. He is the second expert from the firm to testify for the defense, following Dr. Daniel Wolfe, who previously testified that the damage to O’Keefe’s clothing and Read’s SUV was inconsistent with a collision.
As a biomechanist, Rentschler specializes in analyzing how forces from physics and engineering impact the human body. He testified that a 15 mph collision between a crash dummy’s head and a taillight would not have resulted in a skull fracture, contradicting prosecutors’ claims. Experts on both sides have previously testified that O’Keefe’s injuries align with a backward fall, though the defense’s forensic pathologist, Dr. Elizabeth Laposata, argued he landed on something