UF Animal Forensics Conference 2024: Forensic DNA Analysis witih Ginger Clark

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Our next guest is Ginger Clark, Forensic DNA Analyst.

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Welcome to The Junction.

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Ginger Clark: Thank you for having me.

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DrG: So can you start by telling us what

your background is and how it relates

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to the field of veterinary forensics?

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Ginger Clark: I started out in

conservation and population genetics

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of a variety of different animals.

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My area of expertise is

actually venomous snakes.

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Um, I worked with Canebrake

rattlesnakes for 25 years.

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Um, but the population genetics, you

have to figure out using DNA, what

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is a species and then what are the

populations associated with those species.

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And what you end up doing

is building large databases.

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And so, if your species are animals

of interest, such as hunting animals

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or, um, other animals that are of

significant interest to people,

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you have large databases that you

can use for statistical analyses.

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And so that's where I started was

conservation of population genetics.

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And a wildlife officer asked me

at some point, could I distinguish

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yes or no, is it white tailed deer,

if he gives me a piece of meat.

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And that's basically where I started.

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And the challenge of each of those kinds

of tests and designing the assays was

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really challenging and interesting.

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And then as I started getting cases,

the different kinds of evidence that

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came in, the different questions

that were asked, those are all things

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that, Keep my imagination and just

keep me doing this because it's

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interesting to try and figure it out.

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Yes, trying to figure it out.

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DrG: That's amazing.

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So what, what are the uses of DNA?

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Like how can we use DNA in forensics?

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Ginger Clark: In a forensic situation,

often the question is, if you have

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a blood splatter, is that, what

organism did that blood come from?

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Is it human?

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Is it dog?

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Is it cat?

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Is it, you know, some other animal

that is going to be of interest?

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Um, and then once you know what

species it is, um, if it's a dog,

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does it go to any of these other dogs?

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Whether it's a deceased animal,

an animal that's being abused,

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an animal that's been stolen.

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Can we compare those two

and put them together?

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And DNA can do that, and that's What's

the, the value of DNA is its ability to be

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able to put all those pieces together and

be reliable, relatable, consistent, and

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be able to take that into a court of law.

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So DNA has been validated for humans.

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We use exactly the same methods

and protocols in animal forensics

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so that we can take that to court.

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DrG: One of the things that you talked

about was using DNA to identify an animal

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as a victim and as a perpetrator, which

we kind of, kind of make sense, but

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then you also discussed about using it

to find out if an animal is a witness.

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So how can animals be

witnesses of a crime?

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Ginger Clark: What happens there

is, the first case of that was a

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man who murdered his girlfriend and

he owned a large, fluffy, white cat.

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And they found that cat's hairs on the

woman whom he said he did not know.

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And so they were able, and they found

those same cat hairs on the jacket

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that he wore when he killed her.

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And they were able to do DNA to

say that those two hairs came

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from the same individual animal.

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So there the cat, by proxy, was a witness.

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And I've done a couple of cases where

it's essentially the same thing.

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Either the suspect has an animal or the

victim has an animal, and that animal's

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DNA shows up on the other person,

and that ties those two individuals

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together in a fairly compelling way

and often in a specific time and space.

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DrG: We talk a lot about the CSI effect,

and I think that DNA is probably one

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of the fields most affected by it.

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How is the public perception wrong

as far as what they expect out of DNA

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based on these shows that they watch?

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Ginger Clark: They assume that it's,

it always works, which it does not.

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They assume that it's fast, uh,

it takes more than 45 minutes.

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Um, And they assume

that it is always right.

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And that's not necessarily the case.

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And the expectation that DNA is going

to have all of the answers is incorrect.

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On TV you see DNA going into a machine

and minutes later it pops up an

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answer with the person's name, date,

birth date, and all this other stuff.

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And often what we get

is "That's interesting.

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Now let's do whatever we can

to see if we can match it to

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something and put it together".

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DrG: I think another misconception

is just the cost, right?

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Like, people think that DNA should

be done in every single case, but

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that's not really feasible, right?

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Ginger Clark: It is not feasible

and it's not always the answer.

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I prefer to do cases where The

officers have really done their

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homework, because then I know it's

probably going to be successful.

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Um, but it's not inexpensive, and

it's not, you know, one of the

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things that happens in human is the

expectation that there's DNA for

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everything, including a bounced check.

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It doesn't, you It doesn't

apply to all the questions.

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DrG: So what type of, what type of

crimes can DNA be used in, in animals?

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Ginger Clark: When we're looking

at animals, if there's um, an abuse

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situation, um, an animal has been beaten,

if there is blood on, say the wall as well

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as the victim, uh, and the perpetrator.

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So we can match those together so we

can put together the the victim and the

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suspect to be able to say this person

inflicted whatever harm it was on an

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animal based on them both having the DNA.

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So DNA gets shared back and forth.

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But certainly cases where animals

are stolen, um, where horses are

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stolen and slaughtered for food, um,

if we can find meat in the freezer,

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blood on the fellow's clothes.

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So it's, it's applicable

to a lot of situations.

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Um, is it a stolen dog?

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Is it, you know, is that the stolen dog?

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Is that the dog's parents?

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So it's not always an abuse thing.

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You know, there might be a question

of paternity of the animal.

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You know, a stolen dog.

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I will still have the dog's bed.

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That looks like my dog.

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Is it the same one?

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DrG: So speaking of paternity, I

discussed with you a little bit ago,

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an interesting case, and I'm changing

a little bit the facts of the events

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of the case, but basically somebody who

bred a dog that had won all of these

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championships, uh, so like a dog show,

award winning dog, and the dog died.

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So the owner said that he had some

of this dog left over and he cloned

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the dog so that he could then sell

the puppies from this cloned dog for

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a high price because it's a show dog.

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So the puppies supposedly would

be coming from the show dog.

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So can DNA help us

determine if that is fraud?

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Ginger Clark: Yes, it can.

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Um, once you have DNA from the so called

clone dog, you have DNA from the puppies.

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If this dog was used for breeding prior

to its death to his death, then you

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would have other puppies and potentially.

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that deceased dog's parents.

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So with that kind of DNA, you can then

look to see what the, uh, paternity is.

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So yes or no, you know, is this dog,

especially if you have puppies prior,

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you should be able to look at that DNA

and say half the DNA comes from him

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with the prior puppies, half the DNA can

be accounted for by him with the next

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group of puppies.

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So yeah, maybe it is a clone.

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In all likelihood, what you'll

find is the DNA from the prior

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puppies doesn't match and cannot

account for that dog being a parent.

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DrG: You were talking about illegal

like meats, um, and that makes me

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think also about the illegal wildlife

trade , so is DNA useful in that?

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Ginger Clark: Yes, it is.

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There's extensive work that's been done

with rhinos and elephants in particular

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and some of the big cats looking at their

DNA and being able to determine where

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those animals were poached from and in

some cases tie them back to specific

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um, poaching rings and um, it's often

associated with drugs and guns and,

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uh, a lot of other illegal activities.

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But the DNA can often identify the

specific, especially with, um, elephants.

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Uh, we can identify the cartel that

has taken that animal and know

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exactly where it's gone, uh, based

on the DNA and the work that's been

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done by colleagues in that field.

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DrG: Any investigators that are

listening to this that are interested

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in submitting DNA, what samples should

they be looking to collect and how

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should they handle those samples?

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Ginger Clark: The samples are going to

be, uh, you sort of need to think about,

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where are you going to get your DNA from?

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So, plucked hairs, plucked

feathers, pieces of hide.

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Pieces of tissue, uh, blood swabs, so

swabs of blood from surfaces, from

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individual animals, clothing, so there's

a whole variety of samples that can be,

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that have the appropriate DNA on it.

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You have to think about your question and

therefore what samples are likely to have

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the DNA that will answer those questions.

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And then submitting it is, you know, once

we're contacted for something, um, we have

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information on how to package and send

material, you know, dry, wet, um, frozen.

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So it needs to be sent quickly and with

a good chain of custody on it because

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you want to be able to take it to court.

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DrG: What are the biggest errors

or mistakes that investigators

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will do when making a submission?

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Ginger Clark: The biggest mistakes

tend to be, with tissue or other

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samples that are messy and not double

bagging, not freezing and sending it

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overnight, not bagging sandy things well,

putting two pieces of evidence in the

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same bag and they should be separate.

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So it's, it's usually a packaging issue

and then not mailing it appropriately.

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Um, if you have something that's

frozen and being sent, it should

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be sent overnight and not ground.

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DrG: So

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Ginger Clark: a lot of problems, I

would say, with like contamination from

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Often there's contamination within a

case that we receive because it hasn't

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been, the individual items have not

necessarily been packaged appropriately.

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And so they touch and contaminate.

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DrG: We know about using DNA for

like criminal cases, but is there

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a use of DNA in like civil cases?

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Ginger Clark: Yes.

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Yes.

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I often do civil cases and often

they're associated with dog maulings.

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So someone is mauled by a dog.

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Uh, there is, there can be a criminal

component to it, but often it's the

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civil case that comes out of it.

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So your dog killed my dog.

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You're not controlling your

dog is a criminal case.

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Um, my loss of companionship,

that's now a civil case.

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So yes, we do have cases that

are civil as well as criminal.

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DrG: So overall, what's the most

common type of cases that you

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are, uh, asked to, to look into?

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Ginger Clark: I, I always have dogfighting

cases, often have cockfighting, and I

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also do a lot of death investigations.

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Where, or near death investigations

where it's, the victim has been, mauled

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or, you know, injured in some way.

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So those are probably the most

common ones at the moment.

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DrG: Excellent.

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Well, thank you very much for

sharing your knowledge and thank

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you for everything that you do.

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Ginger Clark: Thank you for having me.