Curtis McCarty spent over 21 years in an Oklahoma prison – including 19 years on death row -for a murder he did not commit before he was exonerated through DNA testing three years ago this week. Prosecutorial and forensic misconduct played a role in his wrongful conviction.

McCarty was an acquaintance of an 18-year-old Oklahoma City woman who was found murdered in late 1982. Forensic scientist Joyce Gilchrist initially compared hairs discovered at the crime scene and determined that they did not match McCarty’s, but evidence now shows that she altered her notes after he was arrested three years later. McCarty was initially sentenced to death in 1986, but appeals would overturn his conviction and sentence two more times in the next decade. He was sentenced to death three times before he was finally exonerated through DNA tests on evidence from the crime scene in 2007.

Forensic analyst Joyce Gilchrist was fired in 2000, due to evidence of forensic fraud she had committed in several cases. Her false testimony has contributed to at least two other wrongful convictions that were later overturned by DNA testing, those of Jeffrey Todd Pierce and Robert Miller.

Read more on this case.