Your fingerprints reveal more than you think Simona Francese
Do you ever stop and think,
during a romantic dinner,
“I’ve just left my fingerprints
all over my wine glass.”
(Laughter)
Or do you ever worry,
when you visit a friend,
about leaving a little piece of you behind
on every surface that you touch?
And even this evening,
have you paid any attention
to sit without touching anything?
Well, you’re not alone.
Thankfully, criminals underestimate
the power of fingerprints, too.
And I’m not just talking about
the twisted parting of lines
that make our fingerprint unique.
I’m talking about
an entire world of information
hiding in a small, often invisible thing.
In fact, fingerprints
are made up of molecules
that belong to three classes:
sweat molecules that we all produce
in very different amounts …
molecules that we introduce into our body
and then we sweat out
and molecules that we may contaminate
our fingertips with
when we come across substances
like blood, paint, grease,
but also invisible substances.
And molecules are
the storytellers of who we are
and what we’ve been up to.
We just need to have
the right technology to make them talk.
So let me take you on a journey
of unthinkable capabilities.
Katie has been raped
and her lifeless body has been found
in the woods three days later,
after her disappearance.
The police is targeting three suspects,
having narrowed down
the search from over 20 men
who had been seen
in that area on the same day.
The only piece of evidence
is two very faint,
overlapping fingerprints
on the tape that was found
wrapped around Katie’s neck.
Often, faint and overlapping fingerprints
cannot help the police
to make an identification.
And until recently,
this might have been the end of the road,
but this is where
we can make the difference.
The tape is sent to our labs,
where we’re asked to use
our cutting-edge technology
to help with the investigation.
And here, we use an existing form
of mass spectrometry imaging technology
that we have further developed and adapted
specifically for the molecular and imaging
analysis of fingerprints.
In essence, we fire
a UV laser at the print,
and we cause the desorption
of the molecules from the print,
ready to be captured
by the mass spectrometer.
Mass spectrometry measures
the weight of the molecules –
or as we say, the mass –
and those numbers that you see there,
they indicate that mass.
But more crucially,
they indicate who those molecules are –
whether I’m seeing paracetamol
or something more sinister,
forensically speaking.
We applied this technology
to the evidence that we have
and we found the presence
of condom lubricants.
In fact, we’ve developed protocols
that enable us to even suggest
what brand of condom might have been used.
So we pass this information to the police,
who, meanwhile,
have obtained a search warrant
and they found the same brand
of condom in Dalton’s premises.
And with Dalton and Thomson
also having records for sexual assaults,
then it is Chapman that may become
the less likely suspect.
But is this information
enough to make an arrest?
Of course not,
and we are asked to delve deeper
with our investigation.
So we found out, also, the presence
of other two very interesting molecules.
One is an antidepressant,
and one is a very special molecule.
It only forms in your body
if you drink alcohol
and consume cocaine at the same time.
And alcohol is known to potentiate
the effects of cocaine,
so here, we now have a hint
on the state of mind
of the individual
whilst perpetrating the crime.
We passed this information to the police,
and they found out that, actually,
Thomson is a drug addict,
and he also has a medical record
for psychotic episodes,
for which presumably
the antidepressant was prescribed.
So now Thomson becomes
the more likely suspect.
But the reality is that I still don’t know
where these molecules are coming from,
from which fingerprint,
and who those two fingerprints belong to.
Fear not.
Mass spectrometry imaging
can help us further.
In fact, the technology is so powerful
that we can see where
these molecules are on a fingerprint.
Like you see in this video,
every single one of those peaks
corresponds to a mass,
every mass to a molecule,
and we can interrogate the software,
by selecting each of those molecules,
as to where they are present
on a fingermark.
And some images are not very revealing,
some are better,
some are really good.
And we can create multiple images
of the same mark –
in theory, hundreds of images
of the same fingerprint –
for as many of the molecules
that we have detected.
So step one …
for overlapping fingerprints, chances are,
especially if they come
from different individuals,
that the molecular composition
is not identical,
so let’s ask the software
to visualize those unique molecules
just present in one fingermark
and not in the other one.
By doing so,
that’s how we can separate
the two ridge patterns.
And this is really important
because the police now are able
to identify one of the two fingerprints,
which actually corresponds to Katie.
And they’ve been able to say so
because they’ve compared
the two separate images
with one taken posthumously from Katie.
So now, we can concentrate
on one fingerprint only –
that of the killer’s.
So then, step two …
where are these three
molecules that I’ve seen?
Well, let’s interrogate the software –
show me where they are.
And by doing this,
only portions of the image
of the killer’s fingerprint show up.
In other words,
those substances are only present
in the killer’s print.
So now our molecular findings
start matching very nicely
the police intelligence about Thomson,
should that fingerprint belong to him.
But the reality is that that print
is still not good enough
to make an identification.
Step three:
since we can generate hundreds of images
of the same fingerprint,
why don’t we superimpose them,
and by doing so,
try to improve the rich pattern
of continuity and clarity?
That’s the result.
Striking.
We now have a very clear image
of the fingerprint
and the police can run it
through the database.
The match comes out to Thomson.
Thomson is our killer.
(Applause)
Katie, the suspects and the circumstances
of the crime aren’t real,
but the story contains elements
of the real police casework
we’ve been confronted with,
and is a composite of the intelligence
that we can provide –
that we have been able
to provide the police.
And I’m really, really thrilled
that after nine years of intense research,
as of 2017,
we are able to contribute
to police investigations.
Mine is no longer a dream;
it’s a goal.
We’re going to do this wider and wider,
bigger and bigger,
and we’re going to know
more about the suspect,
and we’re going to build an identikit.
I believe this is also a new era
for criminal profiling.
The work of the criminologist
draws on the expert recognition
of behavioral patterns
that have been observed before
to belong to a certain type,
to a certain profile.
As opposed to this expert
but subjective evaluation,
we’re trying to do the same thing,
but from the molecular makeup
of the fingerprint,
and the two can work together.
I did say that molecules are storytellers,
so information on your health,
your actions, your lifestyle,
your routines,
they’re all there,
accessible in a fingerprint.
And molecules are
the storytellers of our secrets
in just a touch.
Thank you.
(Audience) Wow.
(Applause)