Semen Analysis

While precise legal definitions vary by states and jurisdictions, rape is the term commonly used to mean non-consensual sexual intercourse, including vaginal, anal or oral penetration. MD Criminal Law Title 3. Other Crimes Against the Person Subtitle 3. Sexual Crimes § 3-303. Rape in the first degree § 3-304. Rape in the second degree § 3-305. Sexual offense in the first degree § 3-306. Sexual offense in the second degree § 3-307. Sexual offense in the third degree § 3-308. Sexual offense in the fourth degree

It is estimated that one in 5 women and one in 71 men are raped in their lifetimes in the United States. Together, that's more than 23.6 million survivors.  

Outline Biological characteristics of semen Spermatozoa Detection of semen Presumptive vs confirmatory tests Presumptive tests for semen Detection of sperm “Christmas Tree” stain Confirmatory test for semen

Biological Characteristics of Semen Typical ejaculation 2-5 ml of semen, 160 million sperm 3 pg DNA/sperm = 480,000 ng DNA/ejaculate Only 1 ng DNA needed for STR typing! Seminal fluid Medium for ejaculation Enzymes and other proteins Acid Phosphatase (AP), Prostate Specific Antigen (PSA), and semenogelin Sperm cells- Spermatozoa

Gathering Evidence Semen is an extremely good source of DNA BUT… Not all semen stains contain sperm Vasectomy- blocks sperm from being ejaculated Semen still produced DNA typing probably not possible Infertility Depending on severity, DNA typing may be possible

Spermatozoa Three distinct regions: Head – acrosome and nucleus (with haploid DNA) Middle Piece (mitochondria) Tail (flagella; mobility)

Presumptive Tests for Semen Semen fluoresces under ALS UV light Crime Lite (500 nm) Lots of false positives Alternative light source

Presumptive Tests for Semen Acid phosphatase enzyme Advantages High levels in fresh semen stains Very fast, inexpensive Can be done in the field Limitations Activity may be weak or absent in older stains Also present at low levels in vaginal fluid and bacteria Not species-specific

Presumptive Tests for Semen Overlay method Spray filter paper with distilled water Lay the paper down over the suspected semen stain Leave in contact with stain 30-60 seconds Remove paper circle from stain and spray with AP spot solution Look for a rapid color change to purple Positive acid phosphatase overlay assay

Presumptive Tests for Semen Spot test method Wet sterile cotton swab with distilled water Roll swab across stain Saturate swab with AP solution

Presumptive Tests for Semen Prostate-specific antigen (PSA) Major protein in seminal fluid Also detected in urine, fecal matter, sweat, milk but at much lower levels Half-life of dried stain: 3 years Detected with immunochromatographic test strip assay

Presumptive Tests for Semen Immunochromatographic test strip assay Rapid and simple Specificity still under debate Rapid Stain Identification (RSID-Semen)

Positive RSID™ semen test human semenogenlin monoclonal gold-labeled murine anti human semenogelin antibody to epitope 1 monoclonal unlabeled murine anti human semenogelin antibody to epitope 2 polyclonal unlabeled goat anti murine antiglobulin C

Negative RSID™ semen test C Negative RSID™ semen test

Conclusive Detection of Sperm Microscopic examination “Christmas Tree” stain Nuclear Fast Red stains nuclei red Picroindigocarmine stains tails green Acrosomes don’t stain well in primate sperm

Preserving evidence Victims should make every effort to save anything that might contain the perpetrator’s DNA, therefore a victim should not: Bathe or shower Use the restroom Change clothes Comb hair Clean up the crime scene Move anything the offender may have touched

On February 7, 2014, Maryland Delegate Heather Mizeur introducedlegislation that would require each law enforcement agency to report the total number of untested rape kits in its custody to the Governor's Office on April 1 of every year. HB 1341 would also require health care providers who conduct rape kit examinations to provide the survivor with contact information for the law enforcement agency with jurisdiction over her or his case. When an agency receives a request from a survivor for information about the status of the kit, they would have to respond within 30 days with the status and any results of analysis. Unfortunately, the bill did not pass before the end of the legislative session. 

Rape Kit Backlog http://www.endthebacklog.org/ “We cannot be sure of the total number of untested kits nationwide because most jurisdictions do not have systems for tracking or counting rape kits. Only three states—Illinois, Texas and Colorado—require law enforcement agencies to count, track and test their untested kits. There is no federal law mandating a nationwide movement toward tracking and testing rape kits, despite efforts by some members of Congress to pass such legislation.”