(gentle music)
- Missing persons, kidnapping, murder.
Knowing where to search
for victims-of-crime and other evidence
is crucial for not only solving the crime,
but providing closure to families and loved ones.
You might be thinking isn't that exactly
what forensic science is for?
Isn't that what we see on shows like CSI?
The team identify the suspect,
establish a search area, and close the case.
But what if we don't know where the crime scene is?
What if the suspect is not cooperating with police?
It might not surprise you, if I told you that earlier today,
you might have picked up some soil or maybe even some dust,
from your driveway, car park or a garden path.
Although many of us will not go off and commit a crime,
these soil traces left on our clothing, footwear,
or even vehicle can reveal a history of locations
we have been and when we were there.
Together with industry partners,
our research investigates new methods
for predicting the source origin of soil material.
Using Canberra as a model location,
we have undertaken a high-resolution geochemical survey,
covering more than 650 square kilometres,
and including more than 800 soil samples.
We have produced geochemical maps for more than 50 elements,
like arsenic, lead, and copper.
Using this, this then allows us to test various models
and algorithms to best predict the probable source
of soil evidence.
So far, one model in particular,
has been able to correctly exclude
up to 95% of the surveyed area.
This means that from an initial area
of 650 square kilometres,
our model has reduced it to just 30.
This can provide powerful forensic intelligence
to investigators, helping to better direct costly,
and time-sensitive police resources
to focus more quickly on areas of high priority.
While it is not practical to collect soil
from all of Australia, using our approach,
other states and territories can undertake
their own targeted soil surveys
in other key areas of police interest.
Not only will this be a valuable resource
for forensic science,
but equally for other environmental monitoring
and human health applications.
So, next time you see
the dirty footprints on your clean carpet,
just to remember,
a little bit of dirt never hurt,
unless you're a criminal.
Thank you.
(gentle music)