In sexual assault cases, little research has examined differences in forensic medical findings and law enforcement response by victim age across the entire age range. This study addressed this gap by comparing four victim age groups: adults, adolescents over the age of consent, adolescents under the age of consent, and children under 12. Cases were randomly sampled from a statewide database of medical reports on sexual assault examinations conducted in hospital emergency departments, including only cases reported to law enforcement (N = 563). Data were combined from a medical report database, from coding of medical documentation and crime laboratory reports, and from case data provided by law enforcement. Rates for both younger and older adolescent victims and adult victims were comparable, with no statistically significant differences on most variables: penetration, perpetrator use of force, non-genital and genital injuries, presence of biological evidence, generating assailant DNA profiles, DNA match to suspect, hits in the FBI’s DNA database, and law enforcement unfounding (i.e., determining allegations to be false or baseless). Child victims were significantly less likely to have a non-genital injury, and their cases were significantly more likely to be founded by law enforcement. Arrests were significantly more likely when victims were under the age of consent. Despite significant differences by victim age, similarity between adolescent and adult cases was substantial. Both younger and older adolescents may be at higher risk of physical violence during sexual assault than previously recognized, and need greater attention in response systems.