McDonald’s brain injuries were suffered when his head hit the concrete.
On October 30, 2010, in Sioux City, Iowa, Bradley Gregg and Joseph McDonald were in a physical altercation outside a bar. During the fight, Gregg punched McDonald twice in the head, causing him to fall backward, hitting his head on the concrete. McDonald sustained skull fractures and serious bleeding of the brain, which ultimately resulted in his death. Gregg was accused of involuntary manslaughter and of assault causing serious injury.
Hayes+Associates was retained by Mr. Michael Williams, of the Sioux City, Iowa Adult Public Defender Office to determine if the blows to McDonald’s head were forceful enough to cause his fatal brain injuries or, instead, if McDonald died from his fall and head impact on the concrete sidewalk.
Based on the biomechanical reconstructions of the punching blows to McDonald’s head and the impact to the back of his head from the sidewalk, the H+A analysis showed that while the punch from Gregg likely knocked McDonald unconscious, (a finding substantiated by McDonald’s failure to react reflexively), the punch was not violent enough to cause the fatal head injuries McDonald sustained.
At trial, founder and president, Wilson C. “Toby” Hayes, Ph.D., testified that instead, McDonald’s brain injuries were suffered when his head hit the concrete. Subsequently, after deliberating for three and one half hours, the jury found Gregg not guilty on both counts.
Hayes+Associates, Inc. (https://www.hayesassoc.com) is an expert witness and consulting firm based in Corvallis, OR. The company brings more than 75 years of collective experience in academic research, university teaching and forensic testimony to practice areas that include vehicle collisions, premises safety, slips and falls, products liability, worker safety, sports and recreation, patent litigation and criminal matters.