Forensic examination of human remains is crucial to establish the person’s identity, and cause and manner of death. This way they can have a proper burial, families can get answers, death certificates can be issued and justice can be served.
Body scans can also be used to look for rarer skeletal features, such as fractures, amputations or cancer lesions.
These scientific techniques, either individually or in combination, have been successfully used to identify large numbers of missing persons or disaster victims.
Computerisation, digitisation and miniaturisation of forensic technologies have further improved the identification process. Now, fingerprints, teeth, DNA and medical images can be quickly and easily collected and searched in real time using portable instruments at the scenes of mass disasters.
These methods are only as good as the information we have from when the person was alive. So if someone doesn’t have their fingerprints on file and hasn’t visited a dentist recently, or if close living relatives aren’t available to provide a DNA reference sample or they’ve never had a CT scan, these methods are likely to be useless.
And if a surgical implant doesn’t have unique markings (as in the case of the Queensland crocodile), it makes the task extremely difficult.
So forensic scientists need to explore other methods.
A forensic anthropologist can also study a set of skeletal remains to reveal a lot about that person when they were living — including their sex, ancestry, stature, age, disease and any fatal injuries.
Radiocarbon dating of teeth and bone could tell us when that person was born and died. And the sample’s chemical signature could indicate the region where they were born, lived for long periods or recently travelled. It can even identify what they ate.
Forensic genetic genealogy is also growing in popularity for identifying Jane Does (unidentified females). This is where investigators search a public DNA database of ancestry.com results, looking for genetic links to the DNA from the remains.
Other countries may consider adopting this technique for their cases, as long as the database owners allow law enforcement agencies to keep using the data to identify people.
The best and most efficient way to identify the remains of unknown and missing Australians involves combining expertise from a number of different branches of forensic science and coordinating these efforts nationally.
So for cases where fragments of human remains are found in the stomachs of crocodiles, sharks or some other human predator, investigators now have a toolkit of forensic techniques to choose from to identify the victim.
However, in this most recent case, the recovery of only an orthopaedic device has left forensic scientists with more questions than answers.
Jodie Ward, Director, Australian Facility for Taphonomic Experimental Research; Forensic DNA Identification Specialist, NSW Health Pathology; Associate Professor, Centre for Forensic Science, University of Technology Sydney