George Perrot’s recent exoneration has prompted a review of other Massachusetts cases involving hair comparison analysis. George Perrot was recently released from prison after spending 30 years in jail for a crime he did not commit. Officials have not yet worked out the details on how the review will be carried out, but they have identified at least one case involving hair comparison analysis, but this case also involved a confession by the defendant that was consistent with other evidence and the victim’s injuries.