The remains of iconic bushranger Ned Kelly have been positively identified by forensic scientists more than a century after his hanging in 1880.

The identification was made after an exhaustive forensic analysis of bones found at Pentridge Prison in 2009 – the result of a 20-month process carried out by the Victorian Institute of Forensic Medicine (VIFM), and the forensic DNA laboratory EAAF in Argentina.

DNA taken from the remains was compared with that of Victorian school teacher Leigh Olver, the great-grandson of Kelly’s sister, Ellen.

So how do you go about analysing a skeleton that’s more than 130 years old? And how sure can we be that these old bones belong to our beloved bushranger?

Molecular biologist Dadna Hartman, who performed the DNA analysis for the project, explains the process.

Identifying the remains was a 20-month process. What was involved?

It was similar to the approach you would take to any disaster victim identification. We took forensic evidence in the form of DNA, anthropological evidence and odontology together with the historical evidence we have regarding the execution of Ned Kelly and the whereabouts of his remains.

It really did incorporate a multidisciplinary approach to answer the central question: can we, as a team, identify the remains of Ned Kelly?

We used CT scanning of the remains to look for metal fragments in one of the leg bones – that indicated a shotgun wound.

This then enabled the removal of those metal pellets for further analysis.

We used facial superimposition comparing photographs, or the death mask, to the skull we had.

AAP

How did the DNA identification take place?

DNA was taken from the Pentridge remains (where possible) and they were compared to the mitochondrial DNA profile that we have from the direct maternal descendant of Ned Kelly, Leigh Olver.

Mitochondrial DNA is passed on through the maternal line, so we all have the same mitochondrial profile as our mothers.

All the females in a line will then pass their mitochondrial DNA on to their children.

That really enables us to compare individuals separated by generations.

This mitochondrial DNA profile could be commonly seen in the rest of the population, or it could be one that’s quite rare.

We try gauge how common or rare these are by comparing the profile we’ve obtained to a database.

This particular profile, in the case of Leigh Olver and Ned Kelly, was seen 11 times in a database of more than 12,000 profiles, and all of those hits were to profiles of European descent.

How important was it to have DNA evidence from a living descendant?

DNA was a major piece of evidence in being able to exclude other remains that were at Pentridge, because they did not have the same mitochondrial profile as the DNA from the direct descendant.

The DNA evidence then pointed to the remains that could be those of Ned Kelly, taking the DNA evidence together with the other evidence we had at hand: the anthropological analysis (such as the evidence of wounds, and the age and gender of the remains.

AAP

That, as well as the historical evidence, provided a suite of evidence that enabled us to say with a degree of certainty that these remains are those of Ned Kelly.

What is the margin for error?

The error here will come from how we know whether the profile we’re using has actually come from the bone we’re analysing, and not from somewhere else.

Great caution is taken to ensure the bones are clean before they are analysed.

We ensure the person touching the bone hasn’t contaminated the sample with their own DNA, so someone in the lab would wear gloves and other protective clothing.

But how do you know that many, many years ago, someone hasn’t contaminated those remains?

To combat this, the actual sample used for DNA extraction is taken from within the bone, so it’s less likely to be exposed to the surface.

We have processes in place to ensure we take great care.

We make sure only one sample is analysed at a time.

We would not extract the DNA from the descendant at the same time as the bone sample.

In this particular case, they were done in different labs in different countries, so the risk of contamination for the bones was minimal.

AAP

How was this case different from those you normally deal with?

We were dealing with an individual of historical importance to Australia, so in that context it was very different.

We often deal with investigations into missing persons, which is harder because they don’t have the same high profile.

But we take the same level of care in trying to find out as much information as we can about the missing person.

From my personal perspective, I’m interested in what we can learn from this case and how we can apply what we’ve learned to assist us with normal, ongoing casework, so that when we do have unidentified remains we can reconcile these with missing persons and provide answers to families.

To my mind this case has cemented the importance of having a multidisciplinary approach to forensic analysis, and having a team under one roof that’s able to apply different skills sets to casework.

Those skills are used for important disaster victim identifications, as we did in the Victorian bushfires.

It could be a missing person – this time it just happened to be Ned Kelly.