ANALYSIS OF DATA FROM LARGE AND SMALL POLICE DEPARTMENTS ACROSS THE UNITED STATES SHOWS THAT FEWER THAN 3 PERCENT OF THE CRIMES REPORTED AS RAPE RESULT IN A CONVICTION; MANY CASES ARE NOT FILED OR ARE PLEA BARGAINED TO A LESSER OFFENSE BECAUSE OF INSUFFICIENT EVIDENCE. THIS MANUAL FOCUSES ON A STEP-BY-STEP DEVELOPMENT OF EVIDENCE THROUGH INTERVIEWS WITH THE VICTIM, MEDICAL EVIDENCE OF FORCE, CRIME SCENE EVIDENCE, INTERVIEWS WITH WITNESSES, AND USE OF THIRD PARTY REPORTS (GENERALLY A LOCAL RAPE CRISIS LINE OR VICTIM SERVICES ORGANIZATION). ESTABLISHING A SUSPECT, CONFIRMING THE IDENTIFICATION OF ARRESTEES, AND COLLECTING CORRABORATING EVIDENCE ARE DISCUSSED. SPECIAL ATTENTION MUST BE GIVEN TO ESTABLISHING LACK OF CONSENT WHEN THE VICTIM KNOWS THE ASSAILANT. CRIME SCENE EVIDENCE AND MEDICAL EVIDENCE OF VALUE IN PROVING FORCE ARE GIVEN. SPECIFIC PROCEDURES USED TO PROSECUTE A RAPE CASE ARE SIMILAR TO THOSE USED FOR OTHER FELONIES. HOWEVER, BEFORE A CASE CAN BE PRESENTED TO THE PROSECUTOR, IT MUST BE IN ESPECIALLY GOOD ORDER. IN MOST JURISDICTIONS, SOME TYPE OF PRETRIAL HEARING MUST BE HELD. THE DECISION TO PROSECUTE WILL DEPEND, IN LARGE PART, ON THE STRENGTH OF THE INVESTIGATION AND DEVELOPMENT OF THE EVIDENCE. BECAUSE OF THE MANY EMOTIONAL ISSUES INVOLVED, RAPE INVESTIGATION IS HIGHLY COMPLEX; USE OF A STEP-BY-STEP APPROACH AND A FILING CHECKLIST CAN HELP UNTANGLE THIS DIFFICULT POLICE PROBLEM. SAMPLE MEDICAL AND PATIENT EXAMINATION FORMS ARE PROVIDED.