DETERMINING PAP IS NOW AN ESSENTIAL LABORATORY PROCEDURE IN INVESTIGATING ALLEGED RAPES. THIS IS ESPECIALLY TRUE WHEN THE ACCUSED HAS ASPERMIA OR OLIGIOSPERMA RESULTING FROM CONGENITAL OR ACQUIRED DISEASES, TRAUMA OF THE GENITALS, HAS HAD A VASECTOMY, OR IS A CHRONIC ALCOHOLIC. THUS, THE PRESENCE OF PAP MAY GIVE THE ONLY LABORATORY EVIDENCE THAT VAGINAL PENETRATION AND EJACULATION HAVE OCCURRED. EXAMINATION OF A 13-YEAR-OLD-GIRL RAPED BY HER UNCLE REVEALED NO SPERM BUT A HIGH PAP LEVEL. ALTHOUGH THE UNCLE HAD HAD NO OPERATIONS OR TRAUMA AND HAD SIRED CHILDREN, HE WAS A CHRONIC ALCOHOLIC AND FINALLY ADMITTED THE CRIME. THE CASE OF A WOMAN RAPED BY HER EX-HUSBAND IS SIMILAR. THUS, IN ALLEGED RAPE CASES, POSITIVE PAP FINDINGS WITHOUT SPERM DOES NOT RULE OUT SUSPECTS WHO HAVE CHILDREN AND NO HISTORY OF GENITAL PROBLEMS. ALTHOUGH SEMINAL ANALYSIS IS RECOMMENDED FOR SUSPECTS IN CASES WHERE PAP IS FOUND WITHOUT SPERM, IT IS UNLIKELY THE COURTS WILL ALLOW IT. REFERENCES, ILLUSTRATIONS, AND FOOTNOTES ARE INCLUDED. (PAP)