Forensic study on stains of blood and saliva in a chimpanzee bite case

A case of a boy bitten by a chimpanzee is reported. Forensic investigations were carried out on his T-shirt which had been torn open at the right armpit. By presumptive tests using chemical reagents and definitive tests using antisera against human hemoglobin A (HbAo), human serum and human saliva amylase, it was demonstrated that stains scattered around the torn portion of the shirt consisted of saliva or both blood and saliva. Though the blood was immunologically assumed to be human, the saliva could not be identified as human or chimpanzee. The mixed stains and the saliva stains were grouped A and secretor. By treatment of the mixed stains with a mixture of two volumes of chloroform and one volume of methanol (CM solution), the water-insoluble blood substance derived from blood was typed as O and the water-soluble substance derived from saliva was typed as A and secretor. The former was the victim's blood type and the latter were the chimpanzee saliva types.