With a growing reliance on the various forms of forensic science evidence in complex criminal investigations, the measures for ensuring its quality are facing increasing scrutiny. Improvements to quality management systems to ensure both the robust application of scientific principles and the accurate interpretation and reporting of results, have arisen as a consequence of high-profile rebuttals of forensic science evidence combined with process improvements driven by evaluation of current practice. These improvements are crucial to ensure validity of results as well as maintaining the trust of all those involved in the Criminal Justice System. This work first examines the quality management systems utilised for the examination and analysis of fingerprint, body fluid and DNA evidence. It then proceeds to highlight an apparent lack of comparable quality assurance mechanisms within the field of digital forensics, the newest branch of forensic science. Proposals are provided for the improvement of quality assurance for the digital forensics arena, drawing on the experiences of, and more well-established practices within, other forensic disciplines.

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.