Forensic Files - Season 10, Episode 37 - Hot on the Trail - Full Episode | Forensic Files

[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 2:00 AM and 6:00 AM. 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 ATF, 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 2:00 and 6:00 AM. 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 rapist 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.
86-year-old Lou Edna Jones was unable to get out of her home and died of smoke inhalation.
She had five children, 15 grandchildren, and 20 great-grandchildren. All were traumatized by this senseless act of violence.
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 murder. We knew that, not only had he killed one person that we knew
of in the past, was it going to happen again? NARRATOR: The ATF 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 ATF 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 killed 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, 57-year-old Paul DuBois, 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 12 years in prison. 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 ATF 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 24-hour surveillance, 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 24-hour surveillance.
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.
[theme music]

A serial arsonist was on the loose in Washington, DC.Each of the fires was started with the same type of incendiary device. It was up to forensic scientists to find the clues that lay in the ashes.

Forensic Files is the longest-running true crime series in television history. Evidence and interviews with experts help solve real crimes, disease outbreaks and accidents around the world.

Brief Summary

The episode details the investigation of a serial arsonist in DC, culminating in the capture of Thomas Sweatt through DNA evidence.

Key points

The Arsonist's Identity. Washington, DC faced one of the largest arson sprees in history, leaving investigators puzzled.
A Tragic Loss. The fires resulted in the tragic death of an elderly woman, Lou Edna Jones.
DNA Breakthrough. Investigators found DNA evidence on a cloth wick that survived a fire, leading to a breakthrough.
The Confession. Thomas Sweatt confessed to over 350 fires, revealing a long history of arson.

Episode highlights

Episode quotes

How cold-hearted could you be?

Darlene Lloyd reflects on the arsonist's actions.

4:43WatchJan 14, 2022

Tension

85/ 100High tension

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