Fingerprint Analysis - 2026 Animal ForensiCon with Tonia Smith
The 2026 Animal ForensiCon in Orlando, Florida
Tonia Smith from the Orange County Sheriff's Office shares with us how fingerprints are used in investigations to rule people in/out, what information can be obtained and myths of fingerprint science. She also offers some guidance on collection and submission of evidence that may contain fingerprints.
Transcript
Dr. G:
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:All right, so our last talk for
today was about fingerprints.
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:So that w- lecture was amazing, and as
having taken forensic science a while
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:back and doing the, the fingerprint
stuff, it brought back a lot of memories.
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:So let's start just by telling the
audience who you are and what you do.
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:Tonia Smith: Sure.
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:Uh, so my name's Tonya Smith,
and I am a latent print examiner.
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:I've been an examiner for 24 years,
which sounds terrible, sounds so long.
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:I absolutely love what I do.
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:Uh, I feel very, very fortunate that
I'm able to do something that I feel
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:like I've wanted to do since I was
little, in some form of manifestation.
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:Um, I always wanted to be a cop, as,
you know, long as I can remember.
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:When I learned about detective,
then I wanted to be a detective, uh,
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:learned about forensic science, and
then I knew that that was my avenue.
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:So I actually went to college, and
part of my coursework for crime scene
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:was a fingerprint course, and that
just grabbed me, and that's what
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:I've been able to do for my career.
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:Dr. G:
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:I think, you know, it's kinda like
a similar, different but similar
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:path to what I went through because
I wanted to be a vet and I wanted
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:to do criminalistics, but I wanted
to be a veterinarian, and back then
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:there was no veterinary forensics.
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:And then when the field of veterinary
forensics came up, then it was
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:like, "This, this is it," right?
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:Like I can- Yeah ... merge everything
that I want, and it's kinda nice
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:when you find your passion, right?
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:Tonia Smith: Absolutely.
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:Absolutely.
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:That's awesome.
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:Dr. G:
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:So what is the use and what
are some myths as far as what
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:we can get with fingerprints?
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:Tonia Smith: Yeah.
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:Um, so fingerprints are really
important, in my opinion.
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:Uh, so they, just because you
might find the source of somebody's
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:fingerprint on an item, at a scene, on
a document, that doesn't necessarily
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:mean that they did something bad.
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:It just means that they came
in contact with that item.
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:With regard to investigation and
that kind of thing, you're gonna look
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:at a collaboration of information
that will lead to whether that print
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:actually belongs to somebody that
might have been a suspect in a crime.
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:Um, so as far as, like, a latent
examiner producing results, our results
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:are did somebody touch this thing?
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:And if they did, who are they, right?
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:That's what we're able to provide.
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:Um, so there's a lot of myths out there.
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:I think one of the biggest
ones is that we're automated.
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:So latent print examination is still
very much reliant on human examiners.
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:We do have tools at our disposal.
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:One of the big ones is AFIS, which is
the Automated Fingerprint Identification
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:System, which is kind of a, a generic
catchall at this point Um, but even
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:using that tool, what we're doing is
we're trying to cut down our search time
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:by tapping into a database that with
digital sharing of technology now is much
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:vaster than what it was years ago, uh,
when things kinda remained localized.
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:But even when we look at our
search results, the computer isn't
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:telling us who it belongs to.
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:They're giving us a list of
possibilities, a sh- a short
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:list of possibilities, right?
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:Um, and then we actually have to take
that information, and we sit down
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:and still perform manual comparison.
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:Dr. G:
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:Yeah, I know that somebody asked about AI.
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:Yeah.
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:And that was one of the things
that I thought is, yes, the...
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:You can, you can have a computer tell
you these are consistent, but you
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:really need that person to be able...
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:Because, I mean, you are, you
are comparing so many different
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:details, minute details, right?
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:Tonia Smith: Yes, absolutely.
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:Yeah, there's a, there's a
whole lot of information.
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:One of the other questions that
we get often even in a courtroom
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:is how many points, right?
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:How many points do we need to arrive
at a conclusion of an identification?
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:Uh, well, there's not.
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:There's not a threshold.
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:Um, some agencies may employ a little
bit of a threshold for their own
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:needs, but discipline wide, there's
not a, a set level, and that's
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:because fingerprints vary so much.
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:And there are, um, so many factors that
go into making the decisions that we make.
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:We're not just looking at, um,
ending ridges, bifurcations.
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:We're looking at how they
relate to each other.
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:Where are they spatially on a piece
of, um, a, of a print impression?
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:Uh, and, and what does that look like?
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:And some are more rare.
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:Some arrangements carry more weight
because we don't see them very often.
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:So I always like to use the analogy
that I heard, um, in a training course
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:years ago, which is if you ask me
to give you change for a dollar, you
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:probably are gonna expect that I'm
gonna give you four quarters, right?
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:That's probably the most common.
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:But what if I didn't?
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:What if I gave you two quarters, five
or three dimes, four nickels or three...
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:I'm, I'm mathing terrible.
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:But you get the idea, right?
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:Right.
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:Yeah.
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:If somebody gave you a handful of change,
you're probably gonna remember that.
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:So when you look at the correlation
to ridge detail and arrangements,
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:we, we factor that stuff in too.
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:So sometimes we might need a little
less information because it's just
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:super rare and discriminating.
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:Other times it may be a
little more generic, so we
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:wanna see a little bit more.
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:Dr. G:
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:We talked, um, about the, with like DNA,
the importance of not leaving our DNA
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:behind so that it doesn't, you know, so
that we're not a, a suspect in a crime.
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:Yeah.
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:And, and that's basically the same
thing with With fingerprints, right?
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:Tonia Smith: Yeah, absolutely.
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:Um, anytime somebody's handling
evidence, whether they're on scene,
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:in a lab, handling documentation, we
always have to be mindful of that.
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:We wanna make sure that we're wearing
that protective equipment, glove up,
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:uh, make sure that we're not having
contact with anything at any point
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:in the process, um, because you don't
wanna have your print, um, ki- kinda
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:convolute the details of an investigation.
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:Dr. G:
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:And we think of, you know, every time
that we hear about prints, we think
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:about fingerprints, but can you tell
something about, like, palm prints?
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:Tonia Smith: Yeah, absolutely.
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:So fingerprints is kind of still the
generic term for, um, examination
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:or an examiner, but really,
you can, um, get prints from...
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:Let me kinda back up a little bit.
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:So on the, uh, skin of your hands
and fingers and the bottoms of
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:your feet and your toes, your
skin's a little bit different.
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:That skin is comprised of raised
portions that are called ridges.
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:So all of that skin, when it comes
in contact with a surface, has the
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:opportunity to transfer a replication
of that skin and that arrangement
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:onto that surface, and sometimes
it might be visible, sometimes
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:you might have to process it to
make it a little more visible.
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:Um, either way, all of the impressions
that are left on surfaces that can be
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:preserved can be compared, um, so whether
that be from a palm or the bottom of
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:your foot or toe, not just fingers.
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:Dr. G:
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:So if, uh, if an investigator is, you
know, going through a crime scene and
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:they don't have a fingerprint analyst,
and they're not sure what to do, what's
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:the best way for them to preserve that
evidence so that then you can do your
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:job in, in extracting these prints?
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:Tonia Smith: Yeah.
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:Um, so I would definitely
say, uh, photograph and
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:document as much as possible.
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:Uh, I understand that there are a lot of
agencies out there that might be smaller.
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:They might only house,
um, individual people.
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:Uh, if you don't have somebody
that you can call on, number
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:one, I highly recommend making
that network contact, right?
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:Um, but if you don't, uh,
over-document, um, because you, you
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:never wanna be left with needing
something that you don't have.
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:Uh, I would rather, and my advice would
always be, take the extra pictures.
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:Um, do as much as you can following
whatever policies are guiding
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:you for your agency to do that
processing and preservation and do
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:as much as possible because it's
better to have the extra than not.
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:Um, as far as latent prints,
too, um, don't feel like you have
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:to make the decision if you're
the one doing the field work.
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:So I know that at the agency
that I work for currently, our
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:crime scene investigators seem to
worry a lot about giving us crap,
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:basically is what they call it.
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:Right.
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:Right?
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:But we're the experts.
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:That's what we're there for.
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:We're never gonna be bothered by the
volume that you give us because we know
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:that that's our role and responsibility.
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:So, uh, we also have other tools at our
disposal, so something that you might be
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:trying to look at and analyze and examine
in the field or even back in the office
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:as an untrained latent print examiner,
um, we're gonna have tools that might
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:be able to visualize prints better that
you might otherwise think are no good.
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:So over document and submit
everything that you have.
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:Dr. G:
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:Excellent.
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:Well, thank you so much for
your presentation, and thank you
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:for spending this time with us.
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:Tonia Smith: Yeah.
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:Thank you.
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:I'm, I'm very appreciative of it.
