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Forensic Evidence and Criminal Justice Outcomes in Sexual Assault Cases

NCJ Number
Date Published
April 2018
2 pages
This is a summary report on a NIJ-funded study that examined injury and forensic evidence in sexual assault cases, using data from different types of medical examiners, laboratories, and the police.
The study concluded that although signs of injury and biological evidence may have a substantial impact on criminal justice case outcomes, this impact occurs in relatively few cases. Recommendations for future research in this area include a larger case sample that accounts for more variables that could impact case processing; advanced statistical modeling that includes risk analysis; analysis of jurisdictional differences and case processing across criminal justice and medical systems; and a comparison of how police and prosecutors use biological evidence compared to other types of evidence. Victims often undergo difficult forensic medical examinations in an effort to collect evidence that will improve the likelihood that suspects will be identified, arrested, and convicted. One of the studies reviewed analyzed data from Massachusetts that explored the role of injury evidence and forensic evidence in sexual assault cases, using data from medical providers, crime laboratories, and police. Researchers examined how biological evidence and the type and frequency of injuries were linked to arrest. The timing of evidence collection and arrest was also considered. Researchers determined that just over half of the victims had non-genital injuries, and approximately one-third had documented genital injuries. Researchers noted that the identification of genital injuries could assist police in meeting probable-cause standards. Sexual assault nurse examiners were three times more likely than other medical examiners to document a genital injury. This was perhaps because of their specialized training. Semen was significantly more likely to be found in cases when additional swabbing was completed.

Date Published: April 1, 2018