Identification and Individualization of Semen in the Investigation of Rape

• NCJ Number: 72577
• Author(s): G F Sensabaugh
• Date Published: 1979
• Length: 41 pages
• Grant Number(s): 74NI-99-0041
• Sponsoring Agency: US Dept of Justice; US Dept of Justice NIJ Pub
• Sale Source: National Institute of Justice/
• Publication Format: Document
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America
• Note: Document is missing from the NCJRS collection. No longer available for loan or photocopy.

Annotation

The means for determining that a sexual assault has occurred and for identifying the assailant were the research objectives of this study.

Abstract

The first phases of the research involved determining the limits of the specificity of the acid phosphatase test for semen. The findings showed that the phosphatase found in semen, prostatic acid phosphatase, belongs to a class of tissue acid phosphateses characterized by molecular weight, catalytic properties, and substrate specificities. The vaginal acid phosphatase also belongs to this class. The prostatic and vaginal enzymes may have a common genetic origin and, therefore, differ only in a secondary property. Both enzymes may undergo interconversions such that they are indistinguishable. These observations suggest that the acid phophatase test has limited specificity, and that a significant risk of false negatives exists. In other tests, four commercially available antihuman semen antisera were surveyed and found not to be of adequate specificity for foremsic purposes. To develop an alternative semen-specific test, a protein specific to seminal plasma was sought. Such a protein was identified and named 'protein-30' because its apparent molecular weight is about 30,000 Daltons. The protein appears to be secreted from the prostate gland into the seminal plasma and has not been found in any other secretion. However, further field testing is required. Also, a pigment was discovered which is produced by the action of a bacterium in the seminal plasma. The pigment emits an intense yellow florescence. Identification and characterization of the precursor compound may provide a novel test for semen. For the identification of the assailant, the study found that semen which is uncontaminated by vaginal secretions can probably provide significant genetic information about the assailant. The report is divided into a summary account and a technical section. Data tables and appendixes containing information on other publications by the researchers are included.