The Massachusetts SJC heard oral arguments on November 2, 2022 in Commonwealth v. Eagles, a case regarding hair comparison evidence in homicide cases. The defendant was a lookout for a breaking and entering of what he thought was an empty home and he later went inside to find a man lying on the floor bleeding and the man eventually died. Hair was found on the deceased victim’s hand and the Commonwealth went through various hair comparison techniques and determined that two of the hairs found were consistent with the victim’s head hair, and two other hairs were consistent with the defendant’s head hair.
According to hair comparison statistics at the time of the first trial, there was only about a 1 in 4,500 chance that a hair would match with someone, meaning it is consistent with various hair characteristics. These characteristics include but are not limited to hair shaft, hair length, whether the hair was forcibly removed, etc. It was determined during the first trial that Eagles’ hair matched the hair found at the scene, inferring that he was inside the home during the assault. Additionally, the victim’s hand where Eagles’ hair was found was tucked under his body, and that implied the defendant must have been inside the home when the assault occurred, because it was highly unlikely the hair accidentally got underneath the body.
The defense presented two arguments on appeal: 1) the hair evidence presented at the first trial was recently proved invalid, and 2) the hair comparison statistics were a large determinant in the jury’s decision to convict the defendant of first-degree murder. The statistical evidence about hair comparisons that was presented at Eagles’ trial was generally accepted at the time, but after a report and FBI agreement came out, it became evident that this type of evidence was invalid. The 2009 NAS report revealed fundamental flaws in hair comparison evidence, the most important being that there is no generally accepted number of characteristics required to match in order to deem hairs consistent with someone. And an FBI agreement from 2012 asserted that testimony which explicitly or implicitly suggests a statistical probability of a hair match like in the Eagles case goes beyond scientific proof and is erroneous. The report and FBI agreement became available after the Eagles case, and they cast doubt on this case as well as many others which relied on hair comparison as the main evidence upon which the defendant was convicted.