Original subtitles

A fatal fall at a newlyweds home in Ireland.

A young woman's life cut short just six months

after getting married.

She was a beautiful, caring person.

And what happened was absolutely shocking.

Was it simply a tragic accident?

They find Mary at the foot of the stairs.

She's covered with a heavy duvet

and she's bleeding from her nose and mouth.

Or murder?

Within minutes of actually seeing Mary's body,

I knew there was something wrong here.

I said, "you may sharpen your pencil.

We have a murder investigation."

Mary Gough was born

on the 22nd of December, 1973, in Drogheda in County Louth.

She was born to a large Catholic family

of five children.

Her parents were Marie and James,

and Mary was the only daughter of the family,

and she was described as laid back, independent,

and really friendly, and the heart and soul of the family.

When Mary was growing up,

Pat Marry was a local police officer who would later get

to know Mary's family well.

Mary's family were all very close.

Her father had died when she was very young,

and I guess the fact that she lost her dad brought

the family even closer.

She shone as a person who had a degree of love and compassion,

was just a downright lovely person.

And her mother, Marie, would say

that she was her best friend.

She went to the local secondary school,

and she had the aspirations of all young women of her age.

She wanted to meet someone, get married, have children,

raise a family, do the things that most normal people

would like to do.

In her late teens, Mary

met a man who she wanted to spend the rest of her

life with.

In the early 1990s, when Mary left school,

she got a job in a pub called the Huntsman,

and it was there that she met a man called Colin Whelan.

Colin was a guy from a similar area to Mary,

and he was slightly older than her.

She was 19 years old at the time,

and it became very apparent early on that the two of them

hit it off and they were quite close.

He was very amenable to Mary's friends,

and he was a good-looking guy.

He was over 6-foot.

He was a good catch, let's say.

Colin was an impressive individual.

He went to Dundalk Institute of Technology,

and there he acquired a qualification

in computer science.

And after that, he acquired a job

in Irish Permanent Building Society

to do programming for them.

Mary's career at a law firm was also taking off

and the future looked bright for Colin and Mary.

But in the mid 1990s, their relationship

hit a sudden rough patch.

In 1995, Colin broke up for a period of time with Mary.

She was heartbroken and confided in her mother

and she really was devastated.

And Colin at that stage said he wanted to break it off.

He didn't want to see her again.

But as things progressed, they got back together again

and it appeared to everybody and Mary's family and

Colin's family that the relationship was

going in the right direction.

And he proposed in 1998 for them to get married.

to do it, Mary, and then we'll get you sorted.

On the 9th of September in 2000,

Mary and Colin were married.

On the day, Mary was quite nervous,

but she was comforted by her older brother,

who walked her down the aisle.

The newlyweds quickly settled into married life.

They moved into an area called Balbriggan.

It's 20 miles north of Dublin.

And there, they renovated a new house together.

Newlyweds Mary and Colin

had a lot to look forward to as they embarked on their new

life together.

But just six months after their wedding,

at 12:16 AM on March 1, 2001, an emergency

call was made by Colin.

20 minutes later, the paramedics

and the fire brigade arrived.

They find Mary at the foot of the stairs.

She's covered with a heavy duvet

and she's bleeding from her nose and mouth.

Colin Whelan was stood over his wife's body in a daze.

He was asking paramedics, "is Mary dead or alive?"

As first responders tended to Mary,

they asked Colin what had happened.

Colin claimed that Mary's sleeve

from her dressing gown must have

got caught on the banister, and that's what caused her to fall,

because there was a tear on the sleeve area.

The paramedics found Mary in cardiac arrest.

They began CPR on her in the ambulance

as they rushed her towards Beaumont Hospital in Dublin.

Colin followed the ambulance.

And after Mary's family were informed of her accident,

they rushed to the hospital to be with their daughter.

But when they arrived at the hospital,

they were told that the doctors could do nothing more

and Mary was pronounced dead.

As Colin and Mary's family processed

the devastating news of 27-year-old Mary Gough's tragic

fatal fall, the police, known in Ireland as the "Garda,"

were notified of her passing.

At the time, Pat Marry was a Detective Sergeant

in nearby Balbriggan.

Following standard procedure for all

of a sudden deaths in Ireland, he

was instructed to investigate how Mary had died.

At this stage, Colin Whelan

had made it known that it was only himself and

his wife that were in the house,

and she fell down the stairs.

Colin was then interviewed as a witness

to explain exactly what had happened.

Colin relayed to the Garda in a statement

that he was in, watching the TV.

His wife had gone up to have a shower.

After a period of time, he heard thump, thump, thump.

And he opened the sitting room door and

there on the bottom of the stairs was Mary

and she was unresponsive.

Colin's witness statement

suggested Mary's death was the result

of a tragic accidental fall.

But after speaking to staff at the hospital where

Mary was pronounced dead, officers

had more questions for Colin.

At Beaumont Hospital,

Nurse Galvin went over to sympathize with Colin

and she noticed his shirt opened and

she could see scratch marks.

And Superintendent Thomas Gallagher,

a very experienced detective, spoke with Colin

and he was asked what were they.

And he tried to brush them away and he said,

"oh, when she flailed out of me,

she must have scratched me."

But that's the first time he ever

said that, because that was never an issue on the 999 call

he had made.

He had told her that she wasn't breathing,

she was unresponsive.

But he changed his story when he saw the scratch marks.

As a result of the unusual marks on Colin,

a postmortem was ordered to verify Mary's cause of death

and their home was cordoned off.

Given what Nurse Galvin had seen

and what Tom Gallagher, the Superintendent,

had witnessed the scratches on him,

he thought it best that the house should be preserved

on the basis that if Colin Sweeney's story was not true,

at least they were able to have their house examined.

After Mary Gough's fatal fall down the stairs

at the home she shared with husband Colin Whelan,

police continued to investigate whether her death

was an accident as Colin had claimed.

As part of procedure, they carried out

a background check on Colin.

He was a normal guy.

A good job, well thought of in work.

And there was nothing in Colin's past that anyone should

be concerned about in his relationship with Mary

as far as her family were concerned and his family.

They had a perfect marriage.

They were very happy together.

The day after Mary died,

a state pathologist carried out the postmortem on Mary's body.

I'm Marie Cassidy,

and I was a forensic pathologist

on call when Mary Gough died.

I was brought in because if there was something

unusual about her death, the state pathology department

would be asked to investigate.

Usually in the first instance when I hear about a death,

there's very little information available.

And I don't seek information because I

would rather go in and make up my own mind

about what I think happened.

Within minutes of actually seeing Mary's body,

I knew there was something far wrong here.

This wasn't an accidental death.

This wasn't a death following a simple fall down the stairs.

I didn't see the normal bumps and scrapes

on the arms and the legs I would have

expected in the circumstances.

What I did notice was that Mary's face was discolored.

Normally, after death, the face is rather pale.

Mary's face was not pale.

Mary's face was a blue purple color.

When I looked at the neck, I could

see that there was a distinct line from the neck down.

The skin was the pale color I would normally have expected.

Mid-deck upwards, there was this purple blue discoloration

of the skin, and that was immediately concerning.

She had small pinpoint hemorrhages.

We call these particular hemorrhages,

and I noticed them in and around the eyes.

I then proceeded to do a neck dissection.

This is a very detailed examination,

and I examined the neck layer by layer.

And then I get to the skeleton of the neck.

And that's your Adam's apple, the larynx.

But it was the bone above that, the hyoid bone

I found was broken.

Injuries to the neck structures are not

common in accidental falls downstairs

because you've got a tumbling motion,

and therefore the neck is what we call a protected area.

It does happen.

But if you've only got a neck injury in isolation,

it doesn't quite make sense about this

being a fall downstairs.

Once I found the damage to the hyoid bone

and taking that with the marker across the neck, discoloration

of the face, the small pinpoint hemorrhages in and

around the eyes, this then confirmed

my suspicion that Mary's neck had been compressed.

And at that stage, I was quite firm in that this was a case

of ligature strangulation.

And Mary had been murdered.

It was a shocking discovery

that dramatically changed the course of their investigation.

Marie Cassidy came into the office to me,

and she says "this girl was murdered.

It's not a tragic fall down the stairs."

And I was a little bit taken aback because I

wasn't expecting that.

And she said she's been asphyxiated by strangulation

by way of ligature.

I said to her, how sure are you about this.

And probably a bit cheeky of me asking like, because I

wasn't expecting that.

She says, I'm 110% sure.

Marie Cassidy was quite solid in her findings.

I got on to my superintendent and my very words to him were,

I said, "you may sharpen your pencil.

We have a murder investigation."

Strangulation is actually a very personal method of murder.

And that's because it often involves

looking someone directly in the face as you kill them.

And on top of that, it actually takes

quite a long time for someone to pass away from asphyxiation.

Most commonly then you see asphyxiation murders

in relation to either anger and rage-based murders,

or sexually-motivated murders.

The Gough family had to be

told that it was a murder.

We could see that there were a very close family

and that they were very, very close to Colin Whelan and

his family.

The next day, Mary's brother came down to the station

with his partner and we told him, look,

we're treating this as a murder.

Mary was murdered.

She was strangled, and it's now a murder investigation.

Colin was the only person in the house

at the time with Mary, so it leaves a finger of suspicion

on Colin.

They could not believe what we were saying.

We asked them not to engage with Colin Whelan,

and not to do anything foolish.

Until Colin was made a suspect in Mary's death,

her family had seen nothing to suggest

that he was capable of committing such a horrific act.

From an outsider's perspective, looking

at Colin and Mary's relationship,

there might not be any immediate red flags or

concerns about his behavior or the state

of their relationship, or his likelihood to go

on to harm her, to kill her.

But that doesn't mean that there's not stuff

going on behind the scenes.

There might still have been escalations of behavior

that the general public are just not aware of.

Following the pathologist's findings,

investigators asked Colin about his movements

on the day of Mary's death.

He told them that it was a normal working day,

except that he went to a luxury department store around midday.

Colin, during lunch hour at work,

had purchased a bronze ornament for his wife Mary, and

the lady who served him remembered him

because of him saying he loved his wife

and he wanted to surprise her and all that, you know.

And she thought that was very nice.

Colin was also asked about his whereabouts

after work.

He said, "look, I came home from work."

He changed and went out again to go to the gym.

He was there for an hour, returned home again.

Himself and Mary were there.

They had some dinner.

Officers confirmed Colin's claims by checking

his home security alarm logs.

And with a clean criminal record,

there was nothing to suggest any suspicious behavior

by Colin in the lead up to Mary's death.

Someone escalating from having

no criminal behavior in their past, suddenly all the way

up to murder can happen.

It really depends on the motive behind the murder.

Often, though, what you see in cases of domestic homicide

like this appears to be is there

is normally a pattern of escalation of behaviors

before the moment of murder.

But that doesn't necessarily mean

that anyone's been apprehended or

any criminal charges have been brought

for those prior behaviors.

And a lot of the time, things that we see as red flags or

issues or concerns from someone are

a lot easier to see in retrospect

than they are in the moment.

Within days of Mary's death,

her funeral service took place.

All the Gardas that were involved in the investigation

attended to show their support for the family,

and also to see the reaction of Colin Whelan and his family.

Colin was acting as a cold individual.

He was a big man.

He was 6-foot 5".

He was a well-built man, but he was cold.

He had no emotion in his face.

He had no tears in his eyes.

He didn't put his hands up to his face.

He didn't show any emotion that he was going to bury his wife.

None whatsoever.

Colin appearing very emotionally

withdrawn at the funeral isn't inherently a red flag.

Everyone responds to trauma and loss and grief

in very different ways.

Some people withdraw into themselves, and

so whilst it might not look how everyone would expect someone

to present at a funeral.

It doesn't necessarily indicate anything

sinister in and of itself.

The investigation into Colin Whelan was well underway,

but the police at this point were yet to establish a motive.

Every murder has a motive, and

you have to find that motive.

Because if you find the motive, it will lead you to the killer.

Was Colin having an affair?

Was he trying to get rid of his wife?

Was there financial difficulties?

That's what we needed to determine.

Investigators decided to search for clues

on Colin's computers.

It was decided that it

would be prudent to seize his computers and view them,

to see if there was anything on it of evidential value.

His own personal computer we took from his house.

There was nothing on it.

It appeared to have been wiped, and

there was nothing of evidential value

accruing from that computer.

But when investigators turned to Colin's work computers,

they found he didn't realize that his searches had been

saved to an external server.

They had what they called a double proxy server.

I never heard of that before.

I didn't even know what it was.

And they said, we have a server that

captures absolutely everything that any of our employees

do on a daily basis.

So I said, "you're telling me anything that he looked

up or done would be saved?"

"Yes."

So I said, "happy days."

But getting to Colin's specific computer

activity meant finding a way to navigate through months of data

covering 60 other employees.

They decided that they would devise a program and key it

into the logs and look for key words

like murder or strangulation or that type of thing.

And that's exactly what they did.

What the police found was chilling.

Colin Whelan had been searching terms like asphyxiation,

how to block a windpipe, and how long does

it take to die from choking.

What was sickening to me

is that he was looking up asphyxiation and strangulation

before he got married.

So he had this intention, obviously,

before he got married and played

out the six months of marriage like the perfect husband

and then killed her.

It brought it home to me.

There was no doubt in my mind at that stage

that Colin Whelan had strangled his wife,

and he was the murderer, and that he

had researched how to do it and to make it look like a fall

down the stairs.

It was shocking, really.

In premeditated murders, it is fairly common for someone

to do research before committing the act,

especially if they are planning to try and get away

with it because they're often looking

at different potential murder methods, different ways

to maybe stage a scene or to make it look like an accident.

And all of that's very intentional

for them trying to be organized,

trying to get away with it.

Police also discovered

that Colin took an unhealthy interest in serial killers.

What was hugely relevant was his research

into Henry Louis Wallace, because the nine women he

killed and eventually was caught for,

he had strangled them but never left a ligature mark.

Copycat murders are relatively rare,

but they are well-documented in criminology.

They are understood as a phenomenon.

What you often see in copycat killers

is that they are replicating the behavior of that offender,

perhaps because they share an ideology with them,

or perhaps actually because they

have a sense of grandiosity and they think they can

do the same act, but better.

So you have to wonder, in the case of Colin,

whether he looked at this case, he saw the method by which

these murders had occurred, and he

tried to replicate them thinking

that he could do it better.

Our access to his computer spelt out to us this

cold-blooded and methodical individual

who used the internet to follow his plan.

But we still had not established

at that stage what the motive was for killing his wife.

After investigators established

that Mary Gough died from ligature strangulation,

her husband Colin, who had claimed she fell down

the stairs, became the prime suspect as detectives

continued to search for a motive.

Colin has said it was only him

and her in the house at the time,

and Colin had given up his keys to the house.

So we searched his house.

As a forensic team scoured

Colin and Mary's marital home for clues,

they came across vital evidence in the couple's bedroom.

The blood staining on the wall

between the en suite and the main door

was extremely evident.

When you're being strangled, blood

vessels break in your nose and they

emit blood in a mist format.

And they found that pattern on the wallpaper.

So they knew something had happened in the bedroom

and it was violent.

Their discovery contradicted Colin's claim

that Mary had died after falling

down the stairs on her own.

This is a case of primary scene staging.

So this is where someone has staged the crime scene

specifically with the intention of misleading the police

investigation, because Colin has tried to set this

up to look like an accident.

But now the evidence is showing that actually

there was some sort of confrontation

at the top of the stairs.

The blood spatter analysis is not aligning

with Colin's tale of events.

Investigators also discovered

a vital clue in the duvet Mary was wrapped

in when emergency services first arrived on the scene

following Colin's call.

Wrapped up in the duvet was a yellow towel

and the yellow towel had blood staining on it, which

turned out to be Mary's blood.

And it was a light bulb moment because it

sparked a thought of me about Henry Louis Wallace.

And at every scene of his murders,

there was a towel involved.

And the fact that he had looked up and researched him,

I believe this towel was involved in some way

in the murder of Mary Gough.

Marie Cassidy, the state pathologist who had first

found evidence of ligature strangulation,

also revisited the scene to look for more clues.

Where's the ligature?

What had been tied around Mary's neck?

When I went up the stairs, we had a look around,

and in the bedroom there was nothing very much lying about.

But there was a dressing gown hanging behind the door.

The belt was in place.

It was through the loops, but it

looked as if it had been stretched or something,

and there was some staining on it.

And I immediately brought it to their attention.

And I said, well, that could have been used to strangle her.

The belt was sent to the forensic science

laboratory for testing.

They found Mary's blood on the belt.

Given that the ligature was found in the bedroom

and Mary was found at the bottom of the stairs,

I wondered whether or not she had been strangled upstairs

and then manhandled downstairs.

She'd been literally dragged down

to the bottom of the stairs and then left in a heap.

It was further evidence

that Mary had been murdered, most likely

by her husband, Colin Whelan.

Friends and family were in shock

that Colin was in the frame for Mary's murder,

but Mary's mom Marie said that, on reflection,

there had been a change in her behavior

in the lead up to this.

And looking back as well, Mary's family

said that on her wedding day she just didn't look happy.

Her mother said to me that she just felt

there was something not right.

There was something amiss at the wedding.

She just couldn't put her finger on it,

but Mary wasn't happy and things weren't right.

When the couple came back from their honeymoon,

her mom noticed that Mary was just different.

She stopped getting her nails done

and wearing certain clothes because she said

that Colin didn't like it.

Her mother says she didn't wear her perfume that

she loved, and she said, "oh, Colin doesn't like that perfume

and I don't wear it anymore."

Mary also stopped even inviting her mom around.

And before this, Marie had practically lived in the house.

She had her own bedroom there.

Yet something changed.

And the week before she died, Mary's mom said that she

was calling her every night.

It's as if she wanted to tell her something.

All of this strikes as someone

who's potentially in a coercive,

controlling relationship because now they're married.

Now he has an element of not only legal but sort

of moral control over her.

Manipulators and controlling individuals in relationships

do this on purpose.

They do this to isolate their victim,

and that way they have more control,

more say, over their life.

And so for someone who is seeking that level of ownership

over another human being, these are

very methodical steps that occur

with that exact intention.

Investigators still wanted to establish a motive,

so they turned their attention back

to Colin's digital footprint.

Further searches of Collins computer revealed that he had

actually set up a website and was managing this website

called extramaritalaffairs.com and he was

portraying himself as single and actively

looking for a relationship.

Police then found through this search

that Colin had met a woman in Wales,

and they were having an online affair.

Through communication, through emails,

they had sent a total of something

like 123 greeting cards between each other.

She had nicknamed him "Fuzzy Bear," and he nicknamed

her the "Little Welsh Rabbit."

She was wanting to come over and meet him

because she had fallen in love with him

and was in love with him as a result of this cyber affair.

Colin going to the extent

to set up a whole website just to enable

an extramarital online affair really

goes to show the level of secrecy that he's hiding.

The ability that he clearly has to be

able to manipulate those in his life

because he's presenting as this loving,

doting husband externally.

But the reality of his behavior is so far removed from that.

And I think this is him actually

just testing the limits of what he can get away with.

With the assistance of local police,

detectives decided to visit his online girlfriend in Wales.

The Welsh policeman said, "I have Irish police here.

They want to speak to you and they want to talk to you about

a guy called Colin Whelan."

"Oh, Colin.

Yeah, I haven't heard about him in a couple of days.

I wonder, is he all right?"

We said, "he's fine.

His wife died." "Oh, I know that.

His wife died.

He told me she was killed in a car accident in 1997."

And I says, "no.

His wife died a week ago.

And Colin is the suspect for murdering her."

And with that, she just collapsed on the ground

like, you know.

Continuing their search for digital evidence,

detectives found another potential motive

for Colin to have killed Mary.

An insurance policy document was found, and it showed that,

initially, he had taken out a policy on himself and

Mary on the 15th of March, 2000, for the value

of 200,000 pounds.

But two months after that, he upped the policy

to 400,000 pounds, which was in excess of anything

that was reasonable.

The insurance policy were taken out at a time

after they had been engaged and before they got married.

And when you look at his internet history,

going back before they married, where he was looking up

asphyxiation and strangulation, he obviously had it in his mind

at that stage he was going to kill her

and he was going to cash in.

Also, the internet history showed

he was looking at expensive cars, holidays abroad.

He was looking at the high life if he got this money.

So there is no doubt in our mind

he wanted to kill his wife for that money.

It was definitely the big jigsaw piece that fitted in.

And to say, well, look, this is the motive.

It was financial greed.

We had him bang to rights.

We were quite happy.

We had a very, very strong case.

On April 10, 2001, police drove to Colin's house.

In the presence of his father,

I arrested him on the suspicion of the murder

of his wife, Mary.

Colin Whelan was taken

to Balbriggan Police Station, where the next day

he was questioned about the murder of his wife.

Colin didn't say anything.

He kept his mouth shut.

Now we asked him, "well, can you explain how she ended

up being strangled to death?"

And he said, "I can't."

We asked him, "were you ashamed that

you have killed your wife?"

Like, "have you anything to say?"

And he broke down and he cried.

But he said, "no comment."

He was psychopathic.

That's the way I would look at it.

He believed he was smarter and better than us,

but we were putting questions to him that were hard-hitting.

If he sat there and said nothing, we couldn't care less.

We had the ace card at that stage.

Despite Colin invoking his right not

to comment, on April 11, 2001, police officially

charged Colin Whelan with the murder of his wife,

but he would have to wait over two years to appear in court.

A trial date was set for October 13, 2003.

In Ireland, it's common to grant

bail when there can be long delays, sometimes up

to two years, for murder trials,

provided the accused isn't a flight risk

and won't interfere with the prosecution.

Colin Whelan had strict bail conditions.

He had to sign in every day at Balbriggan Garda Station.

He had to live with his family and

his family had to pay a significant bail bond.

For two years, Colin Whelan

abided by his strict bail conditions,

but seven months before he was due to stand trial,

everything changed.

In March 2003, his family came to the station

to report Colin missing.

So we had to establish where is he.

The family feared the worst and his car was missing.

And we had to establish where his car was

and we had to look for him.

Colin's disappearance sparked a nationwide manhunt,

and on March 12, 2003, police had a breakthrough

on the east coast of Ireland.

The police in Howth had been patrolling Howth Head, which

is a known area for people who commit suicide,

and they observed a car there with keys in it.

And they thought it very suspicious

and they contacted us and I went

up immediately to Howth Head.

I looked at the car and the window was

down on the passenger side.

You could clearly see an empty bottle of gin.

With no idea where Colin was,

police turned to his cell phone activity to look for clues.

His last phone call, we could establish,

was to the Samaritans, which would be consistent

with someone, maybe in a mental state of disorder,

that they would go and throw themselves over the cliffs.

With evidence that Colin

might have ended his life at the well-known suicide spot,

detectives triggered a search for his body.

We had a land and sea search carried out

by the Irish Coast Guard to see if his remains were

on the cliffs or in the sea.

Those searches were negative.

Detectives soon suspected

that Colin had staged the scene to suggest

that he was upset, drunk, and had taken his own life.

I said to myself, "this is typical

Colin Whelan controlling."

He's no more throwing himself off the cliff

than the man in the moon.

And wherever he is, I don't know but I'm going to find him.

I think that this scene staging really

goes to actually show Colin's narcissistic tendencies,

because this is someone who thinks that he's

so intelligent, he can outsmart the law,

he can think of every preconceived idea and question

and answer them by setting up this scene.

But actually, what he's not accounted

for is that the perfect nature of the scene

actually raises questions in itself.

With Colin Whelan now a fugitive on the run,

Irish detectives launched an international manhunt.

When someone like this has vanished,

you have to engage Interpol and Europol

to circulate the details of Colin Whelan

and what he's wanted for.

And you have to step back and let that take its course.

It may take a short time, it may take a very long time,

but you can do no more than that.

One year on, Colin Whelan

continued to evade justice.

But in July 2004, around 16 months after he disappeared,

investigators received a tip off.

This was an unusual turn of events.

Colin had been spotted over 1,000 miles away

in the glamorous vacation town of Portals Nous on the Spanish

island of Mallorca.

He was working in a bar.

The bar that he was working in was

for customers who had bought yachts of 1+ million pounds.

So there wasn't going to be too many people

from Balbriggan down wandering around there

parking their yacht like so.

He felt relatively safe working there.

But Colin's identity was not as well protected

as he thought it was.

A lady, a holidaymaker just

happened to walk into the bar, and

she engaged with Colin Whelan while she was in the pub

and he told her his name was Cian Sweeney.

And he gave her his name and wrote it down,

signed it on the back of a business card for the pub

and said you'll get me here.

When she returns to Ireland, the Gough family

put in the papers the story about Colin Whelan

that he's missing for so long, had anybody seen him.

And a picture of him.

And she saw it, and she says, "Jesus,

that's Cian Sweeney, that's the guy I was talking to.

That's him."

And she contacted the station and he

was put in contact with her.

She says that's the card he gave me, and he signed it.

I took a statement off her.

I went back and compared it with Colin Whelan's signature

on the statement he made and the writing to me,

and anyone who looked it, was the same.

So I said, this is our man and we needed to get him.

16 months after Colin Whelan went on the run

from Irish police wanted for the murder

of his wife Mary Gough, after first claiming

that she had a fatal fall down the stairs,

he had finally been located.

And Spanish police were poised to arrest him on behalf

of the Irish authorities.

On July the 10th in 2004, at 10:30 PM,

the Spanish civil guard raided the bar

where Colin was working.

He was arrested on the warrant

and he said, "you have the wrong guy.

My name is Cian Sweeney.

You have the wrong guy."

And they took him into custody and took his fingerprints.

And they said, "no, you're Colin Whelan,

your fingerprints match."

And he just put his hands up and he says,

"right, I'm Colin Whelan."

News of Colin's high-profile arrest

spread quickly to Mary's family back home in Ireland.

When Mary's family were told, they

were shocked but so relieved.

They broke down in tears on the phone.

Colin Whelan was finally being brought

back from Spain to face justice for what he did to Mary.

Detective Pat Marry traveled to Spain to bring

Colin Whelan back to Ireland.

I flew out to Madrid to bring him back.

I went down to the cell area and

about halfway down I looked into the right

and there was Colin, standing there on his own,

and he had grown a beard at this stage.

Now, I looked at him and he looked at me.

Our glances together spelled it out.

He knew he was caught and I knew I caught him.

He was handcuffed and put on the plane and I

was chatting to him, and he says,

"you know, you're very lucky."

And I says, "why?"

He said, "another week I was gone to Singapore

and you would never get me."

Whelan saying to the detective,

you know, one more week and I'd have been in Singapore.

I think it kind of shows that he's seeing

this as a bit of a game.

It's almost like he's trying to flex, you know,

that this was a master plan, and

he would have gotten away with it if it wasn't for you

and those meddling kids.

You know, it's a bit gamified, and

it's clearly someone not taking the severity of their actions

seriously, and certainly not showing any remorse

for the death of Mary.

On April 11, 2005, four years

after Mary Gough's murder, Colin

stood trial at Dublin's Central Criminal Court

in one of the most publicized trials

in Irish criminal history.

At the beginning of that trial,

and before any jury were called,

he was arraigned by the court clerk, who read out the charge.

He was asked, "did you, Colin Whelan, on the 1st of March,

killed Mary Gough?"

and he looked round at me, and he just looked at me

for a second or two, and he looked back up at the judge

and he said, "guilty."

Colin Whelan's admission of guilt

stunned the packed courtroom.

The Gough family were very happy.

They were ecstatic.

But I looked around at his family, the Whelan family.

They were gobsmacked.

They could not believe what they heard.

They were convinced that their Colin Whelan was innocent.

There's a few reasons that Colin Whelan

might be pleading guilty.

It might be because he wants the shock and the attention

that this is going to give saying guilty at this moment.

It might be because he knows that by entering a guilty plea,

you're more likely to get a slightly reduced sentence

because you're saving the court a trial.

But it also might be simply because he

knows the evidence is too strong against him,

and there's no way out.

Colin plead guilty, in my mind,

I have no doubt about this, that he didn't want his family

to know the details of what he actually did,

and that would all come out during the course of a trial.

As part of his guilty plea,

Colin issued an apology letter to the Gough family.

He explained he was sorry for what he had done,

but it didn't wash with the Gough family.

It was seen more of an insult and a hurtful, paltry apology.

And it was self-serving, I think, at the end of the day.

On April 12, 2005, Colin Whelan was sentenced

for the murder of Mary Gough.

Addressing Colin, the judge described Mary's murder

as the most calculated and callous

killing he had ever encountered in his entire time in court.

He then gave Colin Whelan a mandatory sentence

of life imprisonment.

Colin had tried to fool

his own family, the Gough family, the Gardas, and

everyone else that would listen to him,

that everything was an accident.

He intended to cash in his 400,000

and swan off to wherever he wanted

to do whatever he wanted.

And that's what he thought.

But unfortunately, his plan came to a sticky end.

Smart and all, and as clever and all as he was,

he just wasn't as clever as the investigator.

And I'm proud that it had a successful outcome

for the Gough family.

This whole case,

from start to finish, really seems

like Colin's attempt to assert control and power

and show off his intelligence.

All of it is him, I think, trying to really manipulate

those around him still.

It's all still about how he's perceived by the public.

And that sort of narcissism is a real common trait

that you see in people with psychopathy.

Mary Gough's death is unfortunately

one of many hundreds that I've dealt with.

I've never forgotten it.

And I've never forgotten her.

And she's one of the ones that stays with me.

And there's a few who do.

I think as a woman, you feel for women

in those circumstances.

You think she was killed by the person that she loved

and who told her that he loved her.

And I think how often women get into a situation like that

and assume that they're going to have the happy ever after,

and then it all goes horribly wrong.

It's just a tragedy.

Over two decades since her death,

Mary is still fondly remembered by those that knew her

and those involved in the investigation.

I can tell you from what I picked up about Mary,

from her friends, from her family,

she was a beautiful, kind, caring person.

She was very diligent, very intelligent.

And what happened was absolutely shocking.

But victims shouldn't be forgot about, like, you know.

And as an investigator, you get to know the deceased even

though you've never met them.

And I felt Mary was really a beautiful woman,

a fine lady that suffered.

And unfortunately, in this world,

there's too many women that go through that.