Crimes (Forensic Procedures) Act 2000 - NSW Ombudsman - NSW ...

Chapter 16. Future directions for DNA
This chapter looks briefly at some new techniques in DNA analysis, and the impact of advances in technology on
police and on public expectations.
16.1. New applications for DNA
The use of DNA in the investigation and prosecution of crime is increasing around the world. In some jurisdictions,
including the United Kingdom and United States, DNA is being used in new ways.
16.1.1. DNA low copy number
DNA low copy number involves a profiling technique sensitive enough to extract a DNA profile from just a few cells.
The United Kingdom’s Forensic Science Service (FSS) explains:
The main application of this technique is to target areas on items where it is believed that an offender may have
transferred DNA through touch, like the residue believed to have come from cells such as skin or sweat, left
in a fingerprint. DNA LCN profiles have also been successfully generated from items such as discarded tools,
matchsticks, weapon handles and grabbed clothing. 1297
Low copy number analysis would generally only be considered where other profiling techniques have been
exhausted. It takes longer than routine DNA analysis. Given its increased sensitivity, there is also a danger that DNA
detected may not in fact be connected to the offence being investigated.
The low copy number technique was used to link Bradley Murdoch to the murder of British backpacker Peter Falconio.
The cable ties used to bind the hands of Mr Falconio’s girlfriend Joanne Lees were sent to the United Kingdom for
analysis by FSS scientists, who were able to obtain a DNA profile using the low copy number technique. Bradley
Murdoch was convicted of the murder. 1298
16.1.2. Familial searching
Familial searching is a technique used to identify a suspect where a DNA profile obtained from a known person is
similar to, but not the same as, a profile obtained from a crime scene. The similarity suggests that the offender may
be a close relative of the person whose DNA profile is known. As the FSS explains:
Familial searching is based on the way in which DNA is inherited within a particular family group, DNA profiles of
individuals who are related to each other being more likely to contain similarities in their DNA profiles than two
unrelated individuals. 1299
Familial searching was used in the United Kingdom in the following cases.
Case Study 90
Three girls were sexually assaulted and murdered in Wales, in 1973. Evidence from the crime scene was
preserved, and a DNA profile obtained in 2002. While it did not match any profiles on the DNA database,
a number of profiles were considered to be close matches, which suggested a familial relationship to the
offender. Having identified relatives, police conducted further inquiries and identified a suspect, who had since
died. The suspect’s body was exhumed, and a DNA sample taken. The profile obtained from the suspect’s
body was the same as the profile obtained from the crime scene. 1300
NSW Ombudsman
DNA sampling and other forensic procedures conducted on suspects and volunteers under the Crimes (Forensic Procedures) Act 2000 283