10x37 - Hot on the Trail

[bunniefuu]

[music playing]

NARRATOR: Washington, DC is
a city steeped in history.

Little known is that
it's home to one

of the largest arson
sprees in US history.

In setting hundreds
of fires, the arsonist

left clues to his identity.

And in the ashes
scientists found them.

[theme music]

[sirens]

NARRATOR: Just
before dawn, there

was a house fire in a middle
class suburb of Washington, DC.

Firefighters put it out
before anyone was hurt.

But it was clear, it
was deliberately set.

PHILLIP PROCTOR:
There was someone

in the home at the time.

He had to have know it.

And he didn't seem to care.

NARRATOR: The fire originated
on the front porch where

investigators found remnants
of a melted plastic gallon

container and a cloth wick.

RAYMOND KUK: There was
some fabric material that

was present, which
turned out to be

consistent with
an athletic sock.

NARRATOR: This was the second
fire in the city in less than a

week.

Both had been set the same
way, with an accelerant

inside a plastic
one-gallon container.

A gas chromatography
test of the debris

identified the
accelerant as gasoline.

SCOTT FULKERSON: They were being
set in the early morning hours

between hours of


They were occurring at
single family residences.

And the origin of the fire
was being found either

on the front porch or the
rear porch of these homes.

NARRATOR: The cloth
wick gave the arsonist

plenty of time to get away.

SCOTT FULKERSON: None of us
had seen that type of device

before.

We were so used to having
Molotov cocktails where they

were lighting them and throwing
them against the structure.

This was one that
was actually being

placed against a structure.

And basically you're
lighting it and walking away.

NARRATOR: Investigators from
the Bureau of Alcohol, Tobacco,

and Firearms, or a A*F, found
another interesting item

in the debris.

Remnants of plastic
shopping bags

revealed how the arsonist
carried the containers

of gasoline and
avoided detection.

SCOTT FULKERSON: And when you're
dealing with one individual who

has showed a pattern of using
a device, which we had not

seen on the streets
very frequently.

We knew that it was going
to be a very difficult case.

NARRATOR: Investigators
urged citizens

to be on the lookout
for individuals carrying

plastic shopping
bags in the middle

of the night between


DAVID STATTER: The public
needs to know this.

They need to know they
have a serial arsonist

in their neighborhood.

Just like you need
to know there's

a r*pist working
your neighborhood.

[sirens]

NARRATOR: But it didn't help.

Over the next two weeks,
there were four more fires,

all within a few miles
of one another, all

set with gasoline
inside a plastic gallon

container placed on a porch.

Investigators asked the
surrounding fire departments

to compile a list of
all suspicious fires

over the past year that started
on the front porch of a home

between 2:00 and 6
o'clock in the morning.

The results were astonishing.

They were 20
additional fires, all

set when people were
inside the homes.

DAVID STATTER:
This has been going

on for a year or two years.

And we want to know,
now, what's going on.

We want the answers.

NARRATOR: Tragically, one of
those fires claimed a life.


unable to get out of her home

and died of smoke inhalation.

She had five children,


and 20 great-grandchildren.

All were traumatized by this
senseless act of v*olence.

DARLENE LLOYD: I have
been so heartbroken.

I will never be the same again.

Since that-- and I mean,
the way she left here.

A senseless death, because
someone wanted their kicks

to sit back and watch a fire.

How cold-hearted could you be?

SCOTT FULKERSON: This is
a first-degree m*rder.

We knew that, not only had he
k*lled one person that we knew

of in the past, was it
going to happen again?

NARRATOR: The A*F and the
local fire investigators

formed a task force
to find the arsonist

setting the
Washington, DC fires.

There were 20 fires set with
plastic gallon containers

full of gasoline and
cloth socks used as wicks.

To gain some insight into
the identity of the arsonist,

investigators called
in Ron Tunkel,

an a A*F criminal profiler.

RONALD F. TUNKEL: Well, how a
person acts in the commission

of their crimes is a
reflection of how they will act

in their day-to-day
noncriminal lives.

When we look at a
crime scene, we're

looking for the more
emotional clues left behind.

NARRATOR: In this
case, the fires

were set in predominantly
black neighborhoods.

For Tunkel this was a
crucial piece of information.

RONALD F. TUNKEL: We're probably
dealing with a black offender.

A white offender or
an Asian offender

probably would have stood out.

NARRATOR: Tunkel believed
the arsonist was very skilled

and organized, most likely
a male in his late 20's

to early 40's, and was probably
unmarried since the fires were

set between 2:00 and 6
o'clock in the morning.

NARRATOR: Investigators were
convinced that the arsonist

followed his
exploits on the news

and knew in that in one of
his fires he'd k*lled someone.

DAVID STATTER:
Setting so many fires,

terrorizing so many
people, he's right up

there with some of the
great criminal minds,

or terrible criminal
minds, that we've

dealt with in the
Washington area.

SCOTT FULKERSON: If we didn't
take him off the street,

he wasn't going to stop.
[siren]

NARRATOR: And that's
what happened.

A few months later,
there was a fire

in a nearby apartment building.

Over 100 residents
were evacuated safely.

The fire started
on the fourth floor

using the incendiary device.

SCOTT FULKERSON: There were
multiple one-gallon containers

of gasoline placed out
throughout the hallway.

NARRATOR: But this
time, investigators

got a badly needed break.

One of the residents,


had some suspicious
burns on his hands.

And his clothes
smelled of gasoline.

His apartment was on the fourth
floor where the fire started.

DuBois had a Ph.D. From
Cornell University,

was $8,000 behind
in his rent, and was

about to be evicted
when the fire broke out.

DAVID STATTER: Some
people got very excited.

Oh my.

This was going to do the
serial arsonist when they

arrested him-- that
that was the guy.

But that didn't
ring right to me.

NARRATOR: That's
because the other fires

were set to single
dwelling homes.

JAMES TRUSTY: What
was striking was

that it was in his own
apartment building.

And we began to think that
was a little bit inconsistent

with everything else that had
happened up until that day.

NARRATOR: And the incendiary
device in Dubois' apartment

building was different
from the others.

It didn't have a wick.

Was it possible that
DuBois was a copycat

and learned how to make the
device from media reports?

SCOTT HOGLANDER: At one
point, the media actually put

the device on TV, what they
thought was being used.

And that was
particularly hard for us

to deal with as a task force,
because now potentially anybody

can go out there, recreate this,
and we would not know if we're

dealing with the
arsonist or a copycat.

NARRATOR: But while
DuBois was in custody,

[sirens]
The fires continued.

[sirens]

Investigators concluded
that DuBois set the fire

in his apartment
building, but that was it.

SCOTT FULKERSON: Mr. Paul DuBois
was not the serial arsonist,

however, responsible
for setting the fire

in his apartment complex.

He was not the arsonist
we were looking for.

JAMES TRUSTY: Well, we learned
a lot about his background

and his life, which
was certainly colorful.

But it was pretty
clear, within weeks

I would say, that this was not
going to be the person that

was responsible for these fires.

NARRATOR: However,
DuBois was convicted

of setting his apartment
building on fire

and was sentenced to


Over the next two months,
there was a fire in every week.

By this time, there
were over 30 of them.

Then investigators
found something.

A piece of the cloth wick
survived one of the fires.

Was it possible
that the arsonist

may have left his DNA
on the burnt cloth?

If so, scientists hoped
they could find it.

In most of the fires set by
the Washington, DC arsonist,

the incendiary device
went up in flames.

But in one case, a piece of the
wick, which was a cloth sock

survived.

On a hunch, scientists swabbed
the cloth with sterile water,

put the swab in a vial, and
added a digest buffer that

eliminates everything
except humans cells.

Miraculously, the sock
contained skin cells.

And they provided a DNA profile
presumably of the arsonist.

KARY TONTARSKI: To have
such good DNA results

for an arson case is
pretty remarkable.

When you think about the quality
of the evidence in terms of how

burned, or how much heat it
may have been subjected to,

it's excellent to be
able to obtain results.

NARRATOR: Why were
skin cells on the sock?

The arsonist hadn't
laundered it.

Unfortunately, the
DNA profile did not

match any in the database
of known criminal offenders.

But investigators got
another huge break.

Three young men, coming home
from work around 2:00 AM,

saw someone sitting
on their porch.

Initially, they thought he was
a burglar and chased him away.

-Hey, you!
What the hell you doing?

-Waiting for Carlos?

-Carlos?
Carlos who?

-I must have the wrong place.
-Yeah, you must.

-What's happening?
-He said he had the wrong place.

NARRATOR: Afterwards,
they found a shopping bag

with a plastic container
filled with gasoline

and a sock tied
around the handle.

SCOTT FULKERSON:
This is our chance.

We finally have an
eyewitness, not only one,

but we have three.

Three witnesses that had
a conversation with what,

in our minds, was
the serial arsonist.

NARRATOR: Analysts
went over every inch

of the bag and the
plastic container

and got yet another break.

They didn't find fingerprints.

But sticking to the
outside of the container

was a single human hair.

RAYMOND KUK: So at that
point, we had a hair.

We didn't know where
the hair came from.

NARRATOR: The hair was
consistent with an African

American.

And it contained the root.

DNA testing of the
hair root matched

the DNA from the burned wick.

The three men
described the suspect

as a middle-aged black
male with short hair,

approximately six feet tall.

Police released this
composite sketch to the media.

But the arsons continued.

JAMES TRUSTY: We realize
as that process wore on,

it was much more likely
that this case was going

to be solved forensically
than through any sort

of eyewitness testimony.

NARRATOR: Then the arsonist
changed his pattern.

Instead of using white
plastic shopping bags

to carry the incendiary devices,
he switched to black ones.

These were uncommon.

SCOTT FULKERSON: The bottom of
the black back, read in part,

made in China for the Cornelius
Shop, that portion of the bag

survived the fire.

NARRATOR: The A*F spoke with
the manufacturer in China

and learned that only two stores
in the Washington, DC area

bought these black
shopping bags.

Both stories were in the general
vicinity of the arson fires.

And the owners agreed to
help with the investigation.

SCOTT FULKERSON: The store
owner provided us access

to his store, to his products.

We established


physical and video surveillance,
on both of these locations.

NARRATOR: And investigators
came up with a way

to individualize every
bag the stores used.

SCOTT FULKERSON: The
task force purchased

a series of alphanumeric
steel chips.

These steel chips had
thermal testing done on them

and would survive
future fire scenes.

NARRATOR: They fastened
a different numbered chip

on to the bottom of each bag.

If investigators found one
of these chips at a fire,

the number would
identify the date,

time, and location of the store.

And security cameras would
show every individual buying

plastic gallon containers
in that time frame.

As the black bags were
put into circulation,

investigators discovered
something else.

An arson dog detected gasoline
on a pair of military dress

pants discarded across the
street from one of the fires.

They were the type
worn by the Marines.

Scientists swabbed the
waistband and discovered

human skin cells.

The DNA profile of
these skin cells

matched the hair found on the
incendiary device and the skin

cells from the burned wick.

SCOTT FULKERSON:
The arsonist either

is a current member of the
Marine Corps, a former member

of the Marine Corps, or
has a close association

with the Marine Corps.

So what do we do?

We go to the Marine Corps.

NARRATOR: Fire investigators
contacted the Naval Criminal

Investigation Service about
the pair of Marine pants

found across the street
from one of the arson fires.

JAMES TRUSTY: When we went
down to the Naval yard

to meet with the
NCIS investigators,

I think we had fairly
thin hopes that they were

actually going to
bring us a suspect.

NARRATOR: But that opinion
was a bit premature.

Naval investigators
said they too

were searching for a serial
arsonist who had been setting

fires to cars in a parking lot
used by military personnel.

A surveillance
videotape showed a man

leaving the scene in his car.

From the license plate, he
was identified as 55-year-old

Thomas Sweatt, a civilian who
had a friend in the Marines.

Sweatt was unmarried
and worked as the night

manager of a fast
food restaurant.

DAVID STATTER: Never heard
Thomas Sweatt's name.

When I found out
who he was, I'd been

in his restaurant, in
that fast food restaurant,

in Northeast
Washington many times.

I was there on the opening
day of baseball in Washington.

He probably served
me or was there.

But I didn't know it.

NARRATOR: Sweatt was never
charged in the military fires

because there was insufficient
evidence against him.

JAMES TRUSTY: There was not
really enough information,

at this point of the
investigation of Mr. Sweatt,

to get a search warrant,
to get court permission,

to get his DNA.

NARRATOR: So the
arson task force

put Sweatt under


In doing so, they discovered
Sweatt lived near the food

store that used the
black shopping bags.

PHILLIP PROCTOR: It's kind
of like Christmas morning.

You're like, oh my goodness,
I can't believe this.

We might be finished with this.

NARRATOR: When Sweatt was
brought in for questioning,

he denied any
involvement and willingly

provided a DNA
sample for testing.

JAMES TRUSTY: Frankly,
if he had not consented,

that might have been a red flag
where we would have focused

even more heavily on Mr. Sweatt.

But he did consent.

And that gave us the opportunity
to do a fairly speedy analysis

to see if he was,
in fact, excluded

or included as the
serial arsonist.

NARRATOR: His DNA matched
the hair, the military pants,

and the most incriminating
of all, the skin cells

on the burnt wick.

SCOTT FULKERSON: Mr. Sweatt
didn't realize that DNA could

be recovered from a fire
that he had previously set.

-You got to remember,
he's operating

for a very long period
of time, on the run,

offending, eluding
this massive manhunt.

He may have been worn out.

And that may have contributed.

NARRATOR: When he learned of
the DNA evidence against him,

Thomas Sweatt confessed to
not only the recent fires,

but some dating back 25 years.

SCOTT FULKERSON: It was
a very emotional time.

It was a very
emotional interview.

During that time, Mr.
Sweatt has provided us

with over 350 fires in
which he is responsible.

The fact that Mr. Sweat
had been undetected,

had been untouched for
a period of 25 years,

he is a prolific
serial arsonist.

JAMES TRUSTY: This
could potentially

be the largest serial
arsonist in the history

of the United States.

NARRATOR: Two people died
in those fires and dozens

more were injured.

JAMES TRUSTY: It was
a pretty astounding

moment for all of us.

You always hope that the
case is going to be solved.

But when it actually
happens, there

is a kind of moment
of stunned silence.

NARRATOR: Investigators think
Sweatt had second thoughts

about setting some of these
fires, which explains why

the young men saw him
sitting on the porch.

We'll never know what's
Sweatt told investigators

about the motive for the fires.

He asked for, and received,
a promise of confidentiality

in exchange for his guilty plea.

About the only thing
that came out in court

was that Sweatt said,
he heard voices,

and that he set fires
to relieve stress.

DARLENE LLOYD: If the
demons in your head

told you to set a fire, if you
were so stressed out that you

had to set a fire,
why didn't you

set your own mother's
house on fire?

So see that's where you can't
say this man was insane.

He had very good sense.

He had sense enough
not to get caught.

NARRATOR: Thomas
Sweatt was sentenced

to two consecutive life terms
without parole plus another 135

years in prison, all because of
that rarest of forensic clues,

DNA, that survived
the heat of a fire.

PHILLIP PROCTOR: Just because
of the nature of an arson scene,

the nature of the fire, to
find basically any evidence,

is remarkable.

To find some DNA evidence,
that is usable DNA evidence

and being able to have
that evidence analyzed

and go towards the case and to
help solve that case, is great.

NARRATOR: The forensic evidence
is proof that even in a fire,

a criminal leaves
some kind of trail.

The trick is to find it.

SCOTT HOGLANDER: There
aren't many cases

that are, in history,
of this magnitude

and investigative
techniques that were used,

the task force concept,
how well it worked, I mean,

it really is a model
that you're not

going to see in any other area.

RONAL TUNKEL: In many respects,
he was a guerrilla fighter.

But he was up against
a superior army.

And there was no
way he could win.

So sooner or later,
he would be caught.