An anomalous origin of the coronary arteries had been implicated as a cause of sudden cardiac death in a case involving a 16-year-old student who suddenly collapsed while running track at school. An autopsy revealed that the right coronary artery arose from the aorta in the left sinus of Valsalva. In order to determine whether the same anomaly was inherent in his brother--an identical twin--a complete cardiac medical examination was conducted. Multi-detector-row computed tomography (MDCT) coronary angiography showed no anomaly at the sinus of Valsalva, which indicates that the anomaly, in this case, was not hereditary. This case exemplifies instances where forensic medicine may intervene to prevent sudden deaths in surviving family members.