Investigative strategy for the forensic detection of sperm traces.
In a retrospective study, the results from 786 samples of alleged sexual assaults during a 5-year period were evaluated. Of the samples, 758 were from female victims and 28 were from male victims. The material examined during this 5-year period consisted of 561 cotton swabs with swabs taken from the genitals, mouth, anus, or skin surface. In addition, textile products were examined 191 times, paper products 23 times, and other evidentiary materials 11 times. The acid phosphatase (acP) test was performed as a preliminary test for all samples, followed by microscopy after Baecchi staining. DNA analysis was performed on 74 samples following individual court orders. The retrospectively evaluated results from this period indicate that additional tests for the detection of sperm on textiles and paper products are dispensable after a negative acP test. This is different for genital swabs, since sperm could be found microscopically in 3% of cases with a negative acP test, and DNA analysis was also successful. However, an individual investigative strategy has to be determined for each case, as, depending on the structure of the case, the evidence of male DNA on a female victim, or on her clothes, for instance, can also have evidentiary value without microscopic proof for sperm.
Evers
Heidrun
H
Department of Legal Medicine, University of Giessen, Frankfurter Strasse 58, 35392, Giessen, Germany.
Heidorn
Frank
F
Gruber
Christin
C
Lasczkowski
Gabriele
G
Risse
Manfred
M
Dettmeyer
Reinhard
R
Verhoff
Marcel A
MA
D000135:Acid Phosphatase / Q000032:analysis; D001003:Anal Canal; D019548:Crime Victims; D004247:DNA / Q000302:isolation & purification; D016172:DNA Fingerprinting; D005260:Female; D005554:Forensic Medicine / Q000379:methods*; D005836:Genitalia, Female; D005837:Genitalia, Male; D006801:Humans; D008297:Male; D008853:Microscopy; D009055:Mouth; D010209:Paper; D011902:Rape; D012189:Retrospective Studies; D012661:Semen / Q000201:enzymology; D012867:Skin; D013094:Spermatozoa; D013194:Staining and Labeling; D020080:Tandem Repeat Sequences; D013784:Textiles
D004247:DNA; D000135:Acid Phosphatase