The recovery of semen from bathwater using the Evidence Recovery System (ERS).
Sexual offences are under-reported and ascertaining accurate offence numbers is difficult. Any methods which could increase the ability to obtain biological evidence or reduce the additional distress associated with reporting a sexual offence may result in an increase in reporting this crime type. The Evidence Recovery System (ERS) is designed to collect trace evidence, including hairs, fibres and biological evidence, from bath or shower water in a non-invasive manner. Initially, samples of semen were placed in baths filled with water, and washing was simulated using a range of body wash products. The water was then drained through the ERS before its filters were subjected to acid phosphatase testing and haematoxylin and eosin staining of spermatozoa. Recovered spermatozoa were then graded accordingly. Following this, the experiment was repeated with the addition of dirt/dust particulates during the washing stage, to simulate recovery of biological evidence in a more realistic environment. The results showed that spermatozoa considered 'easy to find' could regularly be obtained from bathwater using the ERS. It appeared that this recovery was not affected by the presence of different body wash products. When dust/dirt particles were added, the number of spermatozoa recovered increased at two of the evidence collection stages. The difference in recovery was considered to be statistically significant. This study provides evidence to suggest the feasibility of use of the ERS as a method to collect semen evidence from individuals subjected to sexual offences. The recovery of spermatozoa does not appear to be affected by the presence of a body wash, but does appear to be improved when skin cells, hair and other debris are transferred into the water, as would be likely during a bath/shower. Further to this, the possibility of obtaining spermatozoa from the home bath or shower of a victim following a post-offence bathing experience is implied.
Centre for Forensic Investigation, School of Science and Engineering, Teesside University, Borough Road, Middlesbrough TS1 3BA, UK. Electronic address: h.page@tees.ac.uk.
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Centre for Forensic Investigation, School of Science and Engineering, Teesside University, Borough Road, Middlesbrough TS1 3BA, UK. Electronic address: Anna.Sarna@keyforensic.co.uk.
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Sarna
Centre for Forensic Investigation, School of Science and Engineering, Teesside University, Borough Road, Middlesbrough TS1 3BA, UK. Electronic address: lucy.corner@hotmail.co.uk.
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Watts
Centre for Forensic Investigation, School of Science and Engineering, Teesside University, Borough Road, Middlesbrough TS1 3BA, UK. Electronic address: emjaneward@btinternet.com.
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Ward
Centre for Forensic Investigation, School of Science and Engineering, Teesside University, Borough Road, Middlesbrough TS1 3BA, UK. Electronic address: christina.hodgson@hotmail.com.
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Hodgson
Centre for Forensic Investigation, School of Science and Engineering, Teesside University, Borough Road, Middlesbrough TS1 3BA, UK. Electronic address: marta.mckenzie@hotmail.co.uk.
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McKenzie
D000135:Acid Phosphatase; D001494:Baths; D044707:Forensic Sciences / Q000295:instrumentation*; D006801:Humans; D008297:Male; D012661:Semen / Q000166:cytology*; D013094:Spermatozoa / Q000166:cytology*; D013194:Staining and Labeling; D014867:Water / Q000737:chemistry*
D014867:Water; D000135:Acid Phosphatase
Bathwater; ERS; Evidence Recovery System; Evidence Recovery System (ERS); Microfilter; Non-invasive evidence collection; Semen