Charles Dabbs was convicted in 1984 of first degree rape. The victim had been assaulted from behind, dragged into an alley, and forced down a flight of stairs. She lost consciousness, awaking to find two other men with her assailant. One man held her arms, the other her legs, and a third raped her. She identified only one person - the rapist.
At trial, the victim's testimony was bolstered by the fact that she and Dabbs are distant cousins and that the assailant had distinctive clothes that were similar to Dabbs's. A forensic analyst also testified that semen was detected on vaginal swabs and serological testing did not reveal a blood type. The results could have come from either the victim or the perpetrator, but the analyst did not make this clear - saying instead that Dabbs' blood type was consistent with the evidence. When the evidence being tested is a mixed stain of semen from the perpetrator and vaginal secretions from the victim – and testing does not detect blood group substance or enzymes foreign to the victim – no potential semen donor can be excluded because the victim’s blood group markers could be “masking” the perpetrator’s. Under such circumstances, the failure to inform the jury that 100% of the male population could be included and that none can be excluded is highly misleading.
In addition, the analyst said a foreign blood group found on pants apparently worn by the victim could have come from someone other than the victim or perpetrator, but investigators failed to take reference samples from these possible other sources to eliminate them. Based on the identification and incorrect forensic testimony, Dabbs was convicted and sentenced to twelve and a half to twenty years in prison.
In 1990, Dabbs gained access to the evidence for DNA testing and Centurion Ministries, a New Jersey-based nonprofit organization that works to overturn wrongful convictions, agreed to pay for the tests. Though testing on the victim's pants was inconclusive, DNA was successfully extracted from a cutting of the victim's underwear. Dabbs was excluded and his conviction was vacated. Based on this exclusion, the prosecution dismissed the indictment, seven years after Dabbs was convicted.