Factors Affecting Criminal Trial Proceedings
Child sexual-abuse cases have one of the lowest conviction rates of all types of crime. There are many factors that can influence whether a prosecutor will accept a case for prosecution, as well as verdict decisions. In this section, we examine the impact of medical and behavioral evidence on prosecutorial and jury decisionmaking in child sexual-abuse cases.
Next to an offender's confession, medical evidence of physical markers of abuse is considered one of the best forms of evidence. Often, jurors enter into a sexual abuse criminal trial with the expectation that some form of medical evidence will be presented (Werner & Werner, 2008). Such evidence is not available in most cases. When evidence is available, it may not prove whether a child was abused. In a study of 236 sexually abused children, researchers reviewed medical records to determine the frequency of abnormal findings (e.g., absence of hymenal tissue, hymenal lacerations, scarring of anal sphincter tissue) as a result of genital or anal penetration. Examination findings revealed that 28% of cases were rated as normal, 49% were nonspecific, 9% were suspicious, and 14% were rated as abnormal or indicative of abuse/penetration (Adams, Harper, Knudson, & Revilla, 1994).
The association between the presence of medical evidence in child sexual-abuse cases and the case outcome is disputable, with evidence on both sides. In one of the first studies of decision-making in child sexual-abuse cases, researchers concluded that medical evidence nearly doubled the chances of a conviction (Bradshaw & Marks, 1990). Subsequent research has shown that the presence of physical evidence can impact prosecutorial decision-making, in that cases with medical evidence of abuse are more likely to be prosecuted than cases without medical evidence (Brewer, Rowe, & Brewer, 1997). In other recent research, physical evidence was found to be neither predictive, nor essential, for conviction of 115 child sexual-abuse cases that went to criminal trial (De Jong & Rose, 1991). Furthermore, other researchers found that medical evidence was not a significant predictor of whether a prosecutor would accept a child sexual-abuse case for prosecution (Walsh et al., 2008). Unlike medical evidence, behavioral evidence has demonstrated a strong and consistent association with trial outcomes.