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.

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.