02x05 - Newborough and Diallo

[bunniefuu]

[music playing]

NARRATOR: This time, on "K*llers Caught on Camera,"

A doorbell cam witnesses the start of a late-night meet up,

but she doesn't make it home.

It's every parent's worst nightmare.

NARRATOR: The police get involved in the search for her.

NARRATOR: And in the US, a man calls in a fire at his home.

NARRATOR: A woman is trapped inside.

The female in there to you is who?

It's my wife.

MAN: It just sounds like something

bad is happening to her.

WOMAN: We know what happened because the video

tells us what happened.

MAN: I heard some g*nshots.

Drop it.

Whatever it is, drop it.

That does not prove that I k*lled my wife.

MAN: The camera doesn't lie.

[music playing]

NARRATOR: In the UK, in Warwickshire,

the market town of Nuneaton, 25 miles East of Birmingham,

it was home to 23-year-old Megan Newborough and her family.

Megan was the glue that kept everybody together.

She was the instigator in a lot of family gatherings and events.

She was very bubbly--

Cheeky.

--very smiley.

Mischievous.

And very caring.

She had a great sense of humor.

And she was always there for everybody, friends, family

alike.

NARRATOR: Megan's passion for dancing started at an early age.

Megan was desperate to start learning how to dance.

The dancing teacher let her join just before she was two.

She wanted to be the little ballerina with the little tutu.

NARRATOR: She was one of three children.

Megan was incredibly beautiful.

She was so organized.

She bossed us around.

And she was definitely the leader of the pack

between the three of us.

She used to somehow make every situation funny.

She was good for-- she used to get the motivation going.

She'd get the energy in the room.

NARRATOR: Megan got a job in human resources

at a brick factory near home.

ELAINE NEWBOROUGH: Megan was an incredibly hard worker.

Her mentality of applying herself

and working really, really hard and that ethic

just stayed with her.

She wants to get into HR to help others, to support others.

People loved her.

Everybody loved being around her.

[music playing]

NARRATOR: At around 6:30 PM on the evening of Friday,

August 6, 2021, Megan headed out to meet someone from work.

She had arranged to meet someone to go for a walk.

She hadn't dressed up.

She hadn't put makeup on.

So wherever she was going, it was obviously somewhere

she felt quite relaxed.

There was nothing out of the ordinary.

And she said she'd be back in a two hours time.

NARRATOR: By 9:30 PM, the family hadn't heard from Megan.

We went to bed.

I continued sending messages through all

the different platforms.

I woke up around 3:00 in the morning.

Realizing she still hadn't come home,

we knew that there was something wrong.

NARRATOR: With no word from Megan by lunchtime on Saturday,

Megan's father reported her missing to the police.

They checked the Newborough family's home security cameras.

The Newborough family had a ring doorbell.

From an investigative perspective,

they're absolutely fantastic because we get images of people

that we would never normally get from conventional CCTV.

We knew that Megan had left in a vehicle.

We have ANPR--

Automatic Number Plate Recognition.

And so we were able to track the route

that Megan had taken once she'd left her home address.

NARRATOR: Her car was captured on camera 30 miles away

from home at 9:50 PM on the Friday

night that Megan went missing.

I guess it was some relief.

Yes, you know, that she could be alive

and we just got to go and find her.

[music playing]

NARRATOR: The police needed to find out who Megan

went to meet on Friday night.

CLAIRE NEWBOROUGH: We heard little stories about him.

We didn't have the full picture.

He was a guy from work.

The last time we spoke to each other over the phone,

she said that she really liked him.

He treated her well, is what she said.

He would send her a good morning text saying,

"Good morning, beautiful."

And that's all we knew.

Inquiries were made with friends, family, workplace.

And through enquiries, they identified Ross McCullam

NARRATOR: Ross McCullam was a 30-year-old

lab worker at the same Brick Company where Megan worked.

Police found out where he lived.

[music playing]

An officer from Warwickshire Police went to home address

and spoke to the parents of Ross.

Ross wasn't there at the time.

They called Ross on one of their mobile phones

and handed the mobile phone to an officer to speak to Ross.

NARRATOR: Detective Sergeant Charlotte Mee was

looking for clues in the video.

His demeanor here is quite casual.

He doesn't seem overly concerned about her.

He's given a lot of detail.

There's no concern in his voice at all.

He's just intent on telling us the fact

that she's gone to McDonald's for this milkshake.

Therefore, he thinks she's all right.

NARRATOR: Professor Coral Dando is a forensic psychologist.

When people are being deceptive,

that's exactly the type of behavior that we see.

So they talk a lot.

They say a lot.

But actually, their words don't carry very much useful

information for the investigation

or they have a tendency to talk about the minute detail.

Ross has not inquired at all about why we're wanting

to speak with him, what's happened to Megan,

is Megan all right.

This doesn't seem at the top of his agenda.

He wants to tell us about why it wasn't him.

Ross is coming across as being very helpful, a helpful witness.

He's given extra detail, detail of which he doesn't

need to give, including directions to the location

he says he's at.

NARRATOR: Ross provided some information,

but Megan was still missing.

And so was her phone.

Megan's brother John, turned detective.

If you've lost your phone, you can just go on this website.

It will ping it.

A flag will appear in its last known location.

John, being very savvy with the computers,

managed to track a phone, and some family members dashed

over to try and find the phone.

The way we did it was we had mom back at home on our MacBook

pinging the phone.

It was just a live ping.

We knew that phone was alive.

We knew it was there in a bush right next

to a pedestrian footpath.

When the phone was found, my heart sank, yes.

We knew something must have happened, not least

because she hadn't been in touch,

but she's never away from her phone.

At that time, concerns for Megan increased significantly,

and the investigation was changed from one of a missing

person to a kidnap inquiry.

NARRATOR: When police analyzed Meghan's phone,

they discovered a series of messages from Ross.

John Cammegh is a leading barrister

who analyzed all of the communication

between Megan and Ross.

First one was, "You're amazing.

Did you get home OK, baby?"

Next morning, he writes, "I haven't heard back from you.

I hope I haven't done something wrong."

He also left a voicemail at about 11 o'clock that night.

[music playing]

NARRATOR: Police followed Megan's car through cameras

monitoring the license plate all the way to Loughborough College.

Dr. Vasileios Karagiannopoulos is a specialist in cybercrime.

The investigators can hone in on the image

and identify that it might be a male driver in the car,

that there are no other passengers

in that particular car.

NARRATOR: When the car stopped, the person who got out

wasn't Megan.

VASILEIOS KARAGIANNOPOULOS: It gives us a clearer idea

of the complexion, of the skin of the person,

what their height is in comparison

to the car and the car door.

And we can see over here that he's taking

some stuff out of the car.

This is a big bin, and he's looking into that,

getting rid of some stuff in that big bin

and goes back to the car.

NARRATOR: After looking around, the male figure

changed his clothes.

VASILEIOS KARAGIANNOPOULOS: He's brought another pair of trousers

as well, which is showing us that he

is not doing things in a panic.

He's much calmer because he's thought about bringing

a change of clothes.

Now we are seeing that he's disposing

of various different items in the bins

in the surrounding area.

This is showing us that he is being very rational

and is trying to think things through,

how he can get rid of evidence in various different bins

without really putting everything

in one so it can be identified as something

that's perhaps connected.

I think it's also really interesting that he's

gone and taken items and put them in different dustbins,

perhaps trying to second guess what investigators, police

officers might look for because they'll always

look through dustbins and try and find

evidence or information.

NARRATOR: The items discarded at Loughborough College

were recovered by police.

JOHN CAMMEGH: There's a blanket covered

in blood, clothing that belonged to Megan covered in blood.

And one of the most poignant, one of the saddest images

for me, for this whole--

from this whole inquiry was one item that was retrieved

from one of the waste bins.

And it was her glasses.

You see her wearing these glasses on the ring

bell footage as she leaves her home

at 7:30 on the Friday night.

They were angrily bent back as if they'd

been crushed in someone's fist.

And for me, that was powerful because it was a reminder of how

wantonly brutal and evil he was in what he did to it, even

to the extent that he wanted to pulverize her specs in his hand.

He's hiding the items that he's just removed.

This includes items from the house as well as personal items

of Megan's as well as his own.

We can say that this is the same person

that we suspect has committed the k*lling of Megan Newborough.

NARRATOR: Close to midnight on August 7, 2021,

police went to Ross's house to arrest him.

He is in his bedroom when police go and arrest him,

and it's almost like he is embarrassed.

He doesn't want his mom and dad to hear

what he's telling officers.

Straight away, you notice the difference in his body language.

It's completely at odds to the way in which he comes over

on the telephone conversation that he had with the police

officer and also the way in which he presents

himself on the voicemail.

NARRATOR: Police immediately went to Charley road

in Woodhouse Eaves.

At that point, this became a m*rder investigation.

The moment when Megan's body is found,

it was assumed that she was a redhead because their hair was

soaked in blood.

You get knock on the door at 2:30

in the morning on the Sunday morning, and the police came in.

Two police officers arrived, and they informed us

that they believed they found a body

that they believed to be Megan.

And then obviously, the family was destroyed from that point.

We had to go and identify her the next day.

NARRATOR: The autopsy revealed how Megan was k*lled.

She died through strangulation and mercifully would have lost

consciousness very quickly.

But obviously used quite an amount of considerable pressure,

which you could see through the particular hemorrhaging

in the eyes.

What was perhaps most awful was what he did to her

immediately after he strangled her because he

went into the kitchen.

He took a knife from a knife drawer,

and he cut her neck across the front of her neck.

The wound was 13 centimeters across,

several centimeters deep, and so deep that it left striations

on the spinal column.

He said, in police interview, he did that to ensure that she was

dead so that she wouldn't be able to tell people

what a bad man he'd been.

We believe that he was making a real and significant attempt

to decapitate Megan for whatever reason.

Post-mortem mutilation of a body is seen as going one step

further in depravity, in criminal behavior,

in highlighting fundamental issues with personality.

It's unclear what his motive was,

but it seems as if he wanted to carry on and punish her.

It was about being in control, being in charge,

and I think would allow him to bolster his self-esteem.

NARRATOR: Ross's messages to Meghan

provided some clues about his motive.

They start off in a very innocent way.

There's a particular dynamic.

Ross is someone who feels pitifully inadequate, obsessed

with his own shortcomings.

She is eager to make him feel better about himself.

She shows great kindness and moreover, a lot of patience

with him.

And then gradually, the conversations

become a lot more sexual.

What these messages showed us was a man

who had a dark and a deep obsession

with sexual distortion, dominance,

coercion, fear, threat.

His sexual fantasies and ideations

were not just unhealthy.

They were, to the likes of you and I,

potentially very dangerous.

NARRATOR: The messages also revealed

that Megan had met up with Ross the week before her m*rder.

They'd had an assignation in the woods somewhere.

Reading the text carefully, it was apparent

that they'd planned to have some sort of sexual encounter,

but it hadn't worked.

We discover that immediately after that failure,

he goes online to buy the packet of erectile medication.

NARRATOR: It appeared Ross's impotence became a catalyst

for his lethal response.

He knew that the reason that he k*lled her

was because when that moment came, that night,

he let himself down.

He was humiliated.

So he lashes out.

NARRATOR: When the police searched Ross's parents' house

in Coalville, they found evidence of a violent struggle

in the living room.

There was ornaments that had been

knocked down, which we believe is indicative of a struggle.

When Ross was strangling Megan, we believe that she

was fighting for her life.

Ross had tried to tell his parents

that he'd spilt a cup of coffee, and that's why it was wet.

But it wasn't.

It was Meghan's blood that was there.

And there were smear stains along skirting

boards within the hallway.

So we believe that that is where he dragged Megan out as well.

Through the forensic examinations,

we could put together the story of what had happened to Megan.

NARRATOR: After disposing of Megan's body on a country road,

Ross went back home.

CORAL DANDO: He lives this life in a squalid bedroom that is

filthy and covered in rubbish.

It would predict that he's got a disorganized approach to trying

to cover up evidence to try and manage the post-m*rder process.

NARRATOR: Ross, then researched relationships.

His voicemail to Megan at 11:00 PM on the Friday

evening after he'd k*lled her could

now be read in a new light.



after he Google's the question, how to tell

a girl that you love her?

And for me, that was perhaps the most chilling aspect of anything

that he did after he disposed of her body.

NARRATOR: The following morning, Ross also started

searching the names of several serial K*llers

and looking at p*rn*graphy.

He is flicking from image to image

to image until he sends her a text message, "Morning, babe."

It was pretty clear from that that he was getting some sort

of sexual gratification upstairs in a room above where he'd

m*rder*d his so-called girlfriend just what,



By looking at other serial K*llers,

maybe he was thinking that this is the way that he might

progress in the future, that maybe he got a real high

from murdering Megan.

Looking at other serial K*llers, he

may be thinking about the fact that he could now put himself

in that group or potentially think about k*lling

again to get that pleasure.

NARRATOR: Ross McCullam was charged with Megan's m*rder,

but they still had to convict him in a court of law.

In his defense, Ross claimed a loss of control

and diminished responsibility.

He blamed his actions on childhood sexual abuse.

John Cammegh presented the evidence against Ross McCullam

at trial.

He made out that she'd touched him in some way, which had just

triggered this violent reaction over which

he had no control whatsoever, and he started strangling her.

It was as if in some narcissistic way,

he is the victim, and he is compelled against his will

to flip out in a way that culminates in him

violently taking her life.

He strangled her with his hands over her throat

for three minutes.

Three minutes gives you bags of time to pull back and retract.

NARRATOR: The surveillance footage

was crucial in undermining Ross's defense.

JEN GREENWAY: What the CCTV shows is just how in control

Ross was that he was able to form a really strong and solid

mindset to think about what to do with Megan's body,

about how to get rid of her clothing.

It's not really up for debate whether or not

it did or didn't happen.

You can watch it with your own eyes.

I don't think you can underestimate for a moment

how important and crucial digital evidence is

in any investigation nowadays.

NARRATOR: After a six week trial,

Ross McCullam was found guilty.

The jury took just 90 minutes to convict him.

Did he feel any empathy?

Did he feel any sadness or any appreciation for what he'd done?

Absolutely not.

Nothing.

What he did do over and over again was express self pity.

NARRATOR: On December 16, 2022, Ross McCullam

was sentenced to life in prison with a minimum term of 23 years.

ANTHONY NEWBOROUGH: Well, Megan had a whole lot of head of her--

getting married, having children, seeing

her brother and sister shine and move forward.

Everything was just ripped apart on that very evening.

CLAIRE NEWBOROUGH: You lose a part of yourself.

It's gone forever.

How am I going to walk down the aisle, knowing my sister's not

there as my maid of honor?

Like, how am I supposed to do that without her there?

Losing a child it's devastating.

It's life shattering.

It's everybody's parent's worst nightmare.

I just miss everything about her.

She was always there.

You could always, you know, just message,

give her a call, or everything.

I miss everything.

[music playing]

NARRATOR: There were just over 600 murders in the UK in 2022.

Only 7% were by strangulation.

In the US, it's even more rare, only 1%.

Most people who perpetrate sexual homicide,

they're more likely to use strangulation.

They're more likely to do things that

are up close and physical than other kinds

of homicide perpetrators.

Strangulation is a very personal thing

that requires quite a lot of effort,

partly because it's much harder to do.

It's much more personal, as in you're close to physically close

to the victim, as in if you're trying to k*ll somebody,

strangulation is hard compared to using a g*n.

NARRATOR: In the United states, the state of Ohio, Madison

Township, 15 miles Southeast of the capital,

Columbus, September 2021, a desperate situation

has been called in.

[phone buzzing]

NARRATOR: Emergency services were on the scene in minutes.

Commander Victor Boyd from the Madison

Township Police Department was recording

on his body-worn camera.

DISPATCHER: Frank 1,207 217 North.

OFFICER [ON RADIO]: OK.

We got a dispatch call that there was a working house fire.

I drove in to the scene and got as

close as I could and started communicating

with the fire chiefs.

NARRATOR: When Victor arrived, the fire

had already been extinguished.

Outside the house was the man who made the 911 call,



I walked over to Mr. Diallo and spoke to him

and made sure he was OK and made sure his children were OK.

So, what we got here?

He was home.

He got the kids out.

NARRATOR: The kids had been saved,

but not everyone had made it out.

[radio chatter]

OFFICER: 3532 Noe Bixby, we've got a structure fire,

and we've got a body on the inside.

DISPATCHER: Oh, God.

Yeah.

There's a body inside there?

OFFICER: That is correct.

They're saying this fire was in the room

that this body is found in.

NARRATOR: Firefighters confirm the body is female.

Commander Victor Boyd questions Mamadou

to find out who the woman is.

The female in there to you is who?

It's my wife.

VICTOR BOYD: It's your wife. MAMADOU DIALLO: My wife.

OK. What is your wife's name?

Fatoumata Diallo.

VICTOR BOYD: Spell the first-- - F-A.

VICTOR BOYD: F-A.

T-A.

NARRATOR: While, his wife, Fatoumata was lying

inside the house, police and the fire service

tried to work out what happened.

It sounds like from him, she must have been babysitting

the two kids when he was gone.

VICTOR BOYD: And he just happened to come home in time?

He just came home and opened the door,

and it was full of smoke.

Kids were still in there playing around on the floor,

and he got them out, but couldn't go back in for her.

I went and started talking to the fire chief,

getting some more clear information

of what is inside the house.

Do you have any idea, was she alive when this--

It's hard to tell.

I can't believe that--

I don't know.

NARRATOR: The blaze itself was small.

Outside, there was no obvious sign of fire.

But inside, Victor Boyd was faced with a gruesome scene.

Once I walked over to the window and I looked in,

I looked down.

I could see the body directly on the floor below me.

The whole room was black inside, burnt and charred really bad.

Her arms were kind of in a position

like this, which is a normal reaction to a body that burns.

NARRATOR: Just a few feet away from his deceased wife,

Mamadou insisted his children were fed.

The restaurant here, they eat after for the kids.

They are hungry.

I told him, you can't leave the scene.

You know, you have to stay here.

There's questions to be answered.

Right now, sir, I understand they're hungry,

but you just can't leave. - OK--

VICTOR BOYD: OK.

Just hold tight.

NARRATOR: Commander Boyd tried to establish

a timeline of events leading up to the fire.

Can you see on your recents what time you called 911?

Let's see, it was right here.



VICTOR BOYD: 1:09?

You got home here at about 13:09?

MAMADOU DIALLO: Something like that, yes.

NARRATOR: The 911 call was made at nine minutes past 1:00.

Victor questioned Mamadou to find out

where he'd been that morning.

VICTOR BOYD: Before you came here and stopped, where--

were you making a run, making a delivery?

No, I went to the shop.

I was talking to him about his time frame

where he had been that morning.

And do you have any idea, sir, off the top of your head

what time you would have been at Medina?



Yeah.

He had said that he had been to a shop

to get his truck worked on.

And then from there, you say you went to the Volvo dealer?

They fixed my ABS sensor on the top.

And from there, he came home.

NARRATOR: Mamadou's reaction raised eyebrows.

Mr. Diallo was a very calm, cool, no sadness, no anything.

I mean, he just answered questions,

and that was about it.

You were at the Volvo around the 11:00?

Yeah, that's what, around the 11:00, yes.

NARRATOR: Police Officer Brandie Krantz

was also called to the scene.

VICTOR BOYD: I got a lot of information to feed you.

OK. VICTOR BOYD: OK?

Yeah.

So when I was on scene, something kind of clicked

that I had met her before.

I know who this person is.

Ms. Diallo moved here from Guinea.

She was very beautiful and was spoken about very highly

by her community.

And unfortunately, she was not treated

very well in her marriage

Mr. Diallo, I've learned that he has a family in Africa,

that he would travel back and see.

He has a wife and children there.

So she was not the only wife that he had.

NARRATOR: Brandie had actually met

Fatoumata when she'd reported Mamadou for domestic violence.

BRANDIE KRANZ: She came to our police department

to file a report about Mr. Diallo's actions

toward her and him wanting her to move out of the house

and not let her have access to the house.

And I know that our officers had responded

out there multiple times to their residents.

I was told by other officers that Mr.

Diallo was not nice to her at all,

did not treat her very well.

NARRATOR: Mamadou's behavior has to be

considered in the context of what was a violent relationship.

One of the reports to the police

was that she had been strangled by him.

Fatoumata reporting repeatedly to the police

is a sort of string of cries for help

that also show that she can't leave him, otherwise,

she surely would have and not just kept reporting.

What's called non-fatal strangulation

is actually characteristic to lots

of domestic violence settings, and it's

massively underreported.

So we don't know just how common it is, also because often it

doesn't leave marks.

And people often feel like they don't have

long-term consequences of being strangled,

and so they don't go to the hospital, for example.

Women who have experienced non-fatal strangulation

within domestic violence settings, a lot of them

have brain injury.

They just don't know it.

At that point, I advised the detectives

that we had history there and that I had just

taken a report several months earlier of a domestic dispute

between her and Mr. Diallo.

[music playing]

NARRATOR: An interview with one of Mamadou's

grown up children also revealed a terrifying picture

of family life.

VICTOR BOYD: We pulled the history up in this house.

We have some pretty, pretty bad domestics here.

Have you?

VICTOR BOYD: Yeah.

NARRATOR: The house was made a crime scene.

Detective Sergeant Bryan Meister from the Sheriff's Office

was called in.

When we get to the scene, it was quite apparent

that something just wasn't right.

I know if one of my loved ones just perished in a house fire,

I would be acting very differently

than the way he was acting.

The female who's in here you said she's your wife?

That's my wife, yes. VICTOR BOYD: OK.

That's what I thought you said.

She birthed me four kids.

VICTOR BOYD: I got you.

NARRATOR: Mamadou's mannerisms were revealing.

You can see how he seems to be trying to manage his body

movements, and he's facing away and he's

trying to really downplay the severity of the situation.

The stereotype of a liar is someone who's nervous, who's

twitchy, who's looking up and to the left, who's avoiding eye

contact, all of which are myths and stereotypes about liars.

But if you overcorrect, then you might

look too calm and too collected, given the circumstances.

[music playing]

Once the Franklin County Detective Bureau arrives

on scene, you could see it in their facial expressions,

the little mm-hmm, little red flags

popping up for them as well.

I went in with the fire investigators,

and we actually viewed the body.

We found a coaxial cable around her neck.

And then once we moved the body, there

was a burnt-up charcoal lighter fluid bottle underneath her.

And that pretty much summed it up that he did something to her.

NARRATOR: The children were put in the care of extended family,

and Mamadou was arrested.

Why he's doing this--

VICTOR BOYD: Because you're riding in his car.

Have a seat.

Thank you.

At that point, they went in and went

through the entire house.

They collected what they needed to collect.

The coroner's office came.

They did their investigation of the body.

NARRATOR: Forensic pathologist Mike

Caplan performed the autopsy on Fatoumata's body.

There was a ligature that was encircling her neck.

The ligature specifically was an electrical

cable that was probably about an 1/8 or 3/16 inch in width.

So we knew right away that that may have played a potential role

in Ms. Diallo's death.

[music playing]

When we're talking about personal weapons,

a USB cord certainly would count as a personal weapon

in that its close.

You have to be physically close to the victim.

And whether or not that's the weapon you always choose

is sort of not really why we'd call it personal.

It's more that you're up close and personal to the victim.

By personal weapon, what the literature means is something

that is physical, that is personal to me,

as opposed to something that's more anonymous

and at a distance.

So sh**ting a g*n, for example, is removed.

It's physically removed.

It's quite emotionally removed compared

to getting up and beating someone or strangling someone.

You're in that person's face.

You're very physically close as opposed to physically

and/or emotionally removed.

NARRATOR: Detectives were eager to ask

Mamadou what really happened.

The victim's obviously no longer with us.

We can't talk to see her side of the story.

NARRATOR: Without Mamadou's testimony,

the police couldn't move forward.

They needed hard evidence to uncover the truth.

I assigned a few guys to do a canvas of the area.

We're looking for cameras in the area, anything that

can further our investigation.

NARRATOR: Mamadou had disabled a security

camera above the front door, but he left

the doorbell cam recording.

This first video clip it shows Mr. Diallo coming

home from wherever he was at.

He pulled up in his truck.

And if you notice the time, the time is 12:24.

The first 911 call came in at 1:09.

He said he came home and found his house on fire.

This totally discredits his story.



So he's taking the kids to the car and attempting to call 911.

He has no sense of urgency.

He is just casually walking to the car with his two kids,

like he doesn't have a care in the world.

And right now, the house is on fire.

NARRATOR: A camera across the street

provided another vital piece of the puzzle.

This is Mr. Diallo's house.

This camera helps us because it's a continuous view.

Nobody else is going into the house.

That means we have no other suspects entering the house that

could set the house on fire.

Mr. Diallo is our key suspect from this video.

NARRATOR: The video ruled out any other potential suspects,

a chilling insight into Mamadou's actions.

As you see here, he's casually walking back up to the house.

He'll go over to where she's located.

And he peers in the window to make sure she's on fire

right there.

NARRATOR: All the evidence seemed to point to Mamadou,

but they needed to prove it in court.

Dr. Mike Caplan's autopsy report provided crucial information

for the case.

It became pretty obvious to me that Mrs. Diallo did

not die from the fire itself.

If somebody dies from a fire, if they're

alive at the time of the fire, they're going to be breathing.

So we're going to see a black discoloration

involving that entire airway going into the lungs.

NARRATOR: But Fatoumata's lungs and airways did not

have any black discoloration.

We were able to find just a little trace of soot

below the level of the vocal cords, but it was very trace.

So it would have been a very short or fleeting time.

NARRATOR: The burns and ligature were obvious.

The carbon monoxide levels, less so.

The fact that we're just seeing just a trace,

a touch of that tells us that she was most likely unconscious

when this fire started.

But she may have taken a few, what we call agonal breaths,

breaths at the end of her life.

So the cause of death in Mrs. Diallo's case was strangulation.

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This form of strangulation is called

strangulation with a ligature.

And so that's anything that you use to wrap

around a neck to cut off air.

In the US, strangulation is an incredibly

rare way to k*ll somebody else.

It's personal.

There's often wrestling.

There's a lot that goes into that, which isn't the case

if you're sh**ting a g*n.

NARRATOR: Police dug into Mamadou and Fatoumata

relationship to try and understand

what motivated him to k*ll.

BRYAN MEISTER: She went over to Africa, back to Guinea to visit.

And when she arrived back home, they said

the relationship was strained.

Something happened over there, but nobody knew what it was.

I think it's easy to see Fatoumata's reporting as a sign

that she had options, but I see it as exactly the opposite.

So, I think, the fact that she had to and chose to report

a number of times to the police that her partner was

violent towards her, I think, that is a sign of a really

Broken and trapped person.

NARRATOR: Mamadou Diallo was charged with fatally strangling

his wife, Fatoumata, with a USB cord

and setting fire to her body in the hope of destroying evidence.

He was sentenced to life in prison with a chance of parole

after 31 years.

If we didn't have the security footage,

it would have been much more difficult to get a conviction.

Security cameras, they just don't paint a picture.

They show you that picture.

VICTOR BOYD: Mr. Diallo got what he deserved.

It's just a shame that he felt he had to do this.

I'm sure the real answers will probably never really come out.

BRYAN MEISTER: He took the mother away from four children.

He took a sister away.

He took a daughter away.

It does give you a sense of accomplishment when you finally

get a conviction and you know he's going to be going

away for a very long time.

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