THE APPLICATION OF DNA PROFILING

• Jurisdiction: Australia

THE APPLICATION OF DNA PROFILING

Overview ....................................................................................................... [80.1000]

Assumptions/Limitations................................................................................ [80.1020]

Contamination ............................................................................................... 80.1040

[80.1000] Overview

The application of DNA profiling has broadened to include not only the specific comparison of a suspect's DNA to DNA found at a crime scene but also large-scale comparisons. DNA profiles from unsolved crimes are now placed onto DNA databases and compared to DNA profiles from other unsolved crimes, suspects, convicted offenders and volunteers (Ayers et al, 2002). To conduct this type of matching, all jurisdictions in Australia have introduced "forensic procedure" legislation which allows for DNA samples to be taken and used for subsequent matching on a DNA database.

The National Criminal Investigation DNA Database (NCIDD) was launched in June 2001 and is currently used for intra and inter-jurisdictional matching of DNA profiles within Australia. As a Commonwealth government initiative, NCIDD is managed by the Australian Criminal Intelligence Commission (ACIC) which was formed in 2016. NCIDD has numerous safeguards to protect the privacy concerns of the individuals whose DNA profiles are contained on the database. Legislation in various Australian jurisdictions also includes heavy penalties for the misuse of the information held on the DNA database. Importantly, each jurisdiction can only see links from the databases that are legally acceptable between both jurisdictions involved in the link. DNA databases such as NCIDD have been used to provide valuable investigative information relating to a large number of unsolved crimes in many jurisdictions around the world. DNA database matching in the criminal context is also being performed on an international scale and is facilitated through Interpol.

During 2017, the ACIC will increase the capability of NCIDD through implementation of kinship calculation software. In use in other parts of the world, kinship calculation software uses complex algorithms to compare DNA profiles looking at genetic relatedness. This can be useful in the identification of unknown deceased persons in missing person cases and disaster victim identification. The addition of this software to NCIDD will allow Y-STR and mitochondrial DNA database searching, as well as the capacity for familial searching in crime scene investigations. Familial searching involves the comparison of a crime scene profile to suspect and convicted offender profiles on a DNA database. The searching process looks for possible relatives to the crime scene profile and therefore requires the different search algorithm to direct match searching. Results of the familial searching produce a list of candidates, in decreasing order of likelihood, who may be related to the source of the crime scene sample of interest. As each successive generation shares its DNA with the next, ancestry or kinship can be traced through the generations. The closer the relative, the more similar the DNA code, that is, mother and child will share 50% of their DNA. Siblings, however, may share 0% -100% of their DNA. This is due to the variation in the random combination of alleles that can be inherited from the mother and the father.

Familial searching can, however, occur inadvertently where the result of a direct match search provides an "almost" match, say with one to two mismatches. This level of match stringency would indicate the match has...