[suspenseful music]
[camera clicking] - [Instructor] See this fly?
It's a floored fly, also known as a coffin fly.
Flies like these provide crucial evidence
in solving mysterious death.
- Insects never lie.
Insects are tiny witnesses.
With my job as forensic entomologists
I use these tiny witnesses to give justice to victims.
- [Instructor] Wired spoke with Dr Paola Magni
to understand how insects can be used
to help solve suspicious deaths.
[upbeat music]
- The forensic entomologists is one of the many experts
that work at the crime scene in order to provide
more information to the course of an investigation.
The postmortem interval or PMI is considered
the time since death.
It is pretty much the time between the moment of death
to the identification of a dead body.
They can provide an alibi to somebody
or destroy an alibi for somebody else.
- Turn Italy, case one.
- The victim was a female that was found
wrapped in a blanket and covered by a carpet.
The pathologist could not estimate at time since death,
the body was highly decomposed.
Typically, the pathologist work within the 72 hours
after death.
After this time, nature takes over
and the typical signs of that, the rigor mortis,
algol mortis, liver mortis cannot be used anymore.
But this is exactly the perfect time for the insects
to colonize the body and start what we call
the biological clock.
That is what forensic entomologists use
to investigate and estimate the time since death.
- [Instructor] Estimating the PMI in this case
relied on analyzing the life cycle of flies
through development from egg to adult can be predicted
based on environmental conditions.
- Insects grow faster or slower
based on the environmental temperature
and there were maggot masses active on the body.
So if outside there were 25 degrees inside
of the maggot mass nearly 28 degrees.
My job in that case was to collect the maggots,
considering the species and temperature
to backtrack the time since death.
That case was very complex.
There was already somebody suspected of this murder
but the insects were giving different information,
giving an alibi to this suspect.
The time since that was around the same time
of a long exchange of messages and phone call
with a certain person helped the investigators
investigate specifically on someone else
asked the right questions and close the case.
- Turn Italy, case two.
- Some insects are interested in the fresh decomposition,
some highly decay, and some when body is just bones.
Based on the kind of insect I can find,
I can can understand from how long the body's there.
So my job was to participate into the investigation
if this person was dead since the last time
he was seen alive or if there was something going on.
The body was nearly mummified by the bugs
and specifically one type of that are called
the larder beetles created a very strange structure.
They were looking like threats on the body.
When the body is mummified or when I find just bones
on a very old body, I use another technique
that is called a successional waves methodology.
- [Instructor] Successional waves refers
to the different types of insects that are found
at different stages of decomposition.
Using this method allows forensic entomologists
to estimate PMI for older cases.
- The case of the forgotten man was pretty complex
because there was an association
of different type of insects.
We had to identify which insects were belonging to the body,
and which one to the house.
All of these insects were giving us information
about how many successional waves had passed by
to estimate the time since death.
We realized that the body was laying
in the place where we found it for at least
a year and a half.
- [Instructor] Western Australia, case three.
- When we watched CSI or similar TV programs,
most of the time investigators found
the presence of a body on the ground.
Reality is that the majority of the cases,
bodies are found contained in something.
We consider that as limited access environment.
Insects have a physical impediment to reach the body,
but they don't give up.
Insects really try their best to reach the body
because the body means food, and the body means
place for the offsprings to grow and survive.
Blow flies will lay eggs on the zip
and the female of coffin flies can pass through the zip
and reach the body.
So there is this consuming food chain
that happened inside of a suitcase that is very interesting
because what we find inside is whatever happened before.
So we can find different successions,
and we can work on that to identify from how long
the body is inside of a suitcase.
Despite these cases happen all around the world
and pretty often, the research is really scanned
because it's very difficult to perform such a huge research.
My group of research is developing this to find out
how insects can interact with a body during
the winter period in suitcases compared to trash can.
These research will allow us to give more information
to investigators if cases like this happen
in Western Australia.
Forensic entomology is really holistic
from the point of view as a discipline
because you consider insects, also had to consider
the investigative process, and has to combine
the information from the insects with the information
about the environment, the methodology
and at the specific crime scene.
What I'm trying to do with my work
is to use this little piece of nature
to give justice to the victim.
[camera clicking]