Forensic evidence findings in prepubertal victims of sexual assault

The American Academy of Pediatrics recommends forensic evidence collection when sexual abuse has occurred within 72 hours, or when there is bleeding or acute injury. It is not known whether these recommendations are appropriate for prepubertal children, because few data exist regarding the utility of forensic evidence collection in cases of child sexual assault. This study describes the epidemiology of forensic evidence findings in prepubertal victims of sexual assault.

The medical records of 273 children <10 years old who were evaluated in hospital emergency departments in Philadelphia, Pennsylvania, and had forensic evidence processed by the Philadelphia Police Criminalistics Laboratory were retrospectively reviewed for history, physical examination findings, forensic evidence collection, and forensic results.

Some form of forensic evidence was identified in 24.9% of children, all of whom were examined within 44 hours of their assault. Over 90% of children with positive forensic evidence findings were seen within 24 hours of their assault. The majority of forensic evidence (64%) was found on clothing and linens, yet only 35% of children had clothing collected for analysis. After 24 hours, all evidence, with the exception of 1 pubic hair, was recovered from clothing or linens. No swabs taken from the child's body were positive for blood after 13 hours or sperm/semen after 9 hours. A minority of children (23%) had genital injuries. Genital injury and a history of ejaculation provided by the child were associated with an increased likelihood of identifying forensic evidence, but several children had forensic evidence found that was unanticipated by the child's history.

The general guidelines for forensic evidence collection in cases of acute sexual assault are not well-suited for prepubertal victims. The decision to collect evidence is best made by the timing of the examination. Swabbing the child's body for evidence is unnecessary after 24 hours. Clothing and linens yield the majority of evidence and should be pursued vigorously for analysis.