To mark International Day of Women and Girls in Science (11 Feb), Natasha Mitchell shares insights into the day-to-day life of a forensic biologist, including solving crime, international travel and rewarding work for the Unrecovered War Casualties-Army.
Natasha Mitchell, Senior Forensic Biologist, Forensic Science SA
The Louise Bell case
I have a real interest in cold cases. Science is always evolving, and there are techniques available today that simply didn’t exist 10 years ago.
I comb through every piece of evidence to see how advances in technology, or simply a new perspective, can breathe new life into cases that were once written-off as dead ends. Is there a different test we can run? Can we detect something that we previously couldn’t?
One of the most rewarding cases I worked on was the investigation into the abduction of 10-year old Louise Bell from her home in 1983. I started to review the case file in 2009, but it wasn’t until I saw some new techniques on an overseas travel scholarship that I made a real break-through.
On that trip I visited the Netherlands Forensic Institute, and connected with some incredible scientists using a technique called ‘low copy number analysis’. This was a more sensitive way to analyse DNA, which is particularly useful when you don’t have a large or complete sample.
I was excited to see how this technology could be used in my cold case, and worked closely with the lab to give it a try. SAPOL were able to transfer some clothing samples to the Netherlands lab, involving careful planning to maintain the integrity of the sample and chain of evidence. It worked! The analysis allowed SAPOL to reopen the case, eventually leading to the trial and conviction of Dieter Pfennig for murder in 2016.
This high profile case was one of my longest, involving six years work. The outcome was incredibly rewarding, from both a professional perspective and a personal one, as it helped give closure to Louise’s family and South Australians.
It also showed me the importance of research and self-learning, including keeping up-to-date with science literature and cutting edge techniques. As a scientist you are part of a global community, and the connections you form with international colleagues are critical.
Going to court
Being a scientist is not just lab and computer work. Part of my job is presenting evidence at trials, where I describe what the science tells us about the case. At the beginning, giving evidence at court was very intimidating! But, like most things, it got easier with practice.
I take my responsibilities in court very seriously. What I say to the jury often holds a lot of weight, with information that can potentially put someone in jail, or exonerate them completely. It is really important that I remain fair and unbiased, and that I consider all the potential scenarios from a scientific perspective.
Going to court helps me to see the real-life impact of my work, as I come face-to-face with the jury, as well as other people involved in the case and their families. Giving evidence has also honed my ability to think on my feet, and remain calm in high-pressure situations, which are valuable life skills.
A scientist in the Army
I work in the Army Reserve when I am not at FSSA, as one of two forensic biologists in the defence force.
I work with anthropologists and archaeologists to recover and identify fallen soldiers from past conflicts. One of the major projects the group has worked on is the recovery and identification of remains from a mass grave site from the battle of Fromelles, which involved hundreds of Australians on the western front in WW1.
My job is to analyse skeletal remains and try to work out who these soldiers are. We use samples from living family members of the missing soldiers, and compare their DNA to see if they are from the same lineage.
This work is really rewarding. Once we know who they are, we can lay our fallen soldiers to rest in a proper and respectful manner. It also has a huge impact on the families, even through the passage of time. Imagine, for instance, if your father or grandfather went missing back in 1916, and we can finally offer you some closure. It is very important work.
Keeping all the balls in the air
I’m a mum with two kids now, so my days are packed full. Forensic Science SA is a very supportive workplace. They are flexible with when I work and how I work, which really can’t be overstated. It allows me to fit my life together in a manageable way so I can do my job well.
In my ‘spare time’, I am the SA branch president of the Australian and New Zealand Forensic Science Society. This is an important professional touch point. We hold regular meetings to discuss interesting cases and new techniques, and contribute to a biennial conference that is attended by approximately 800 professionals.