Original subtitles

I haven't looked at these in so long.

My 21st birthday at Alex's house - me and him together.

He was like a brother.

That's one of the last times we all hung out together.

Everybody was there. We'd all got very, very drunk.

And I'd snuck up on him and jumped on him

with this Winnie-the-Pooh onesie.

Like, we were laughing and having a craic

and it was a good time.

It was a normal, like, night of craic.

Like, I can't... I can't see it as that any more.

Alex went to bed.

His mum came over to us. She'd gotten real close,

and the tone had changed from fun and light to sort of serious.

And she'd said to me that something was going to come out about Alex,

and we needed to be there to support him.

I don't know if anybody actually knew what was going on.

I would hope that nobody knew. It was just him.

Now, every time I think about it, it makes me feel sick.

This programme contains some strong language, scenes which some viewers may find disturbing

and deals with suicide and sexual abuse

BBC NEWS THEME PLAYS

NEWSREADER: Hello. Welcome to BBC News.

One of the world's most prolific online abusers...

He's targeting young females that were bisexual or gay.

..described as offending on an industrial scale.

What's a catfish?

Come on, Alex. You know what a catfish is.

Imagine you've just found out your friend's a massive paedophile.

Hundreds of victims worldwide.

Those figures are going to rise.

Who's doing this? Is it someone from my school?

I know there's more coming.

It's just, how many?

How big is this actually going to get?

What do I have to do to just make it stop?

When he told me there could possibly be thousands,

this person's never going to stop.

SIREN WAILS

I think it's important that the whole story's told.

If it hadn't been for the bravery of one young 12-year-old...

..we wouldn't be sat here now.

She was the catalyst that started it all off.

Just a normal shift.

6.00 or 7.00 in the evening, checked the board.

Police officer in Scotland had sent me some detail of a 12-year-old girl

who had been in a conversation online with a person

that was saying they were a similar age.

That conversation had very quickly become sexual,

and she'd sent an image of herself exposing the top part of her body.

Police in Scotland said at the time of that conversation happening,

the suspect was using the internet at this address in Newry.

Did a little bit of digging, and one person in that house had been linked

to similar sort of things a couple of years before.

It was images on the lower level of the scale, if you like -

so, like, topless images.

I looked at what the other team had done.

He's been investigated 2016, 2018.

It's gone as a report fail, so he's not been charged.

And I just had a feeling that this one needed

a little bit more exploration.

So, yeah. So it was, "Bring him into the custody suite,

"see what he's got to say for himself."

LONG BEEP

This interview is being digitally recorded.

It's being conducted in an interview room at Banbridge Police Station.

The date today is Monday, the 18th of March, 2019.

The time by the clock on the wall is 1456 hours.

Would you state your name and date of birth for me?

Alexander McCartney, 2nd of 4th 1998.

He was real nerdy, just a 20-year-old kid.

Was just in that little rural community.

As to the conversations back and forward,

she has said that she was on Snapchat,

she got a friend request from a girl called Chloe,

said the girl looked to be about 13, 14 years of age,

that the girl had long blonde hair, she was light-skinned.

And she goes on to say that she was sent a picture message,

and when she opened it, it was of a girl that was naked.

She wasn't expecting it. She'd never seen a picture like that.

She states that she was asked to send a picture message back

to Chloe, and she thought that this was strange

and she was confused, but she did it and she doesn't know why.

Did you make contact with that child as Chloe232x?

No comment.

Who's Chloe?

No comment.

She was told, "I have your nudes and facepic

"and you're going to do as I say,

"just for tonight, or I will upload everything for everyone to see.

"Do you understand?"

She started worrying, went and spoke to her mum,

and her mum rang the police.

Have you ever used the Snapchat username Chloe242x?

Er... No comment.

Would you know who that user account would come back to?

No comment.

The investigation started out as a very standard investigation.

With everybody having phones and cameras,

image sharing is massive and this is very common.

She says there was a message from Chloe.

She said, "I'm a catfish." Do you know what that means?

What is it? Explain it to me.

No comment. What's a catfish? No comment.

Come on, Alex. You know what a catfish is?

No comment.

Throughout high school, there was a close-knit sort of group,

and there was about four or five of us.

Like, we'd be split up through classes,

but every lunch time, same place, same people.

I was super close with Alexander.

He was near and dear to me.

And then all of a sudden, that guy that was my friend,

I found out he is a monster.

That changed me, I think.

Every now and then, I'll think about it and I'll just be in disbelief.

Like, how is this real life? How did this actually happen?

MUSIC PLAYS, HE LAUGHS

Tunes!

PRODUCER: You're doing good. Not used to being on camera.

No YouTuber, like.

It's just hard to think about it all again, you know,

and actually lay it out into words?

What is it that you want to say?

Jesus Christ!

HE SIGHS

I was very, very close with Alex McCartney.

I trusted him and I let him into my house, and I was in his. And...

There are so many people he hurt, his actual victims.

But he didn't just directly hurt people,

he indirectly hurt all of us, everyone that trusted him.

Can we break for a second? Sorry.

Jesus Christ.

HE GROANS

Another odd shape here.

Being a teenager was pretty beige.

When I was 14,

somehow I kind of stumbled into this group of people

from different scenes that all hung out -

the likes of me, Lee, Alex.

We can't figure out how this could ever have happened.

You didn't see Lee and Alex very often.

They were part of more the gamers, definitely more of the quieter sort.

I remember walking in and seeing them all playing games

and being competitive.

They always seemed to just kind of keep to themselves -

you know, was a gamer, was an emo.

And what Alex did went so unnoticed for so long.

That's just downright scary.

DS McINNES: Could we have the wrong person here, Alex?

Could this be a young 13-year-old child using your phone?

No comment.

Was there a young girl called Chloe who was 13 at your address

at 2250 hours on the 13th of December 2018, using your phone?

No comment.

I'd remember it.

So is there any reason why you wouldn't remember it?

This is, what, months ago?

OK. So, no.

So do you frequently have 13-year-old girls using your phone?

No. No?

DI HAMILL: What's your knowledge of computers and apps?

No comment.

Do you ever use virtual private networks

to hide your identity whilst you're online?

No comment.

I've got Alex's devices - anything electronic,

capable of connecting to the internet,

or anything that was capable of storing anything -

so, pen drives, SD cards.

I don't have enough evidence at that point.

I need the physical evidence to be able to charge him.

Because you have been arrested in relation to child sexual offences,

I want to give you this list of helplines in case you feel

you need to speak with somebody.

Interview's terminated at 1513 hours.

He was released on bail with certain conditions -

not to have a device capable of accessing the internet.

And whilst I've taken all his devices away from him,

how do you monitor that?

How do you actually keep control of that

without a police officer being present with him 24 hours a day?

You really can't. You really can't.

So that's why getting all that evidence as quickly as I could

was the priority.

# I have a new friend

# She settled down

# And when she comes round, we mess around... #

LEE: It's all I really know, is this place.

It's just a small town.

You can't get away with anything here.

So, how did Alex not get caught?

How could he have done this?

He was just Alex.

You know, we were completely blindsided.

Nobody expected anything.

Some really old stuff from, like, 2014,

last year in high school,

I've never really gone through until now.

Like, I'm not keeping them on purpose.

What's done is done, and deleting that's not going to get rid of it.

Me and Alex.

It looks so normal. We're just messing about.

You know, and now I sort of wish I could forget it.

Our group weren't really, like, popular.

Everyone else was super interested in sports and we weren't.

We all gravitated towards each other because of that.

One big nerd fest.

Alex would have been the one I was definitely closest with,

more close than the rest, I think.

If anyone had a problem, he'd be one of the first people

to ask if you were OK. And he was this nice, funny, genuine guy.

One time in school, I was horrendously bullied.

One guy was getting all up in my face and he'd be messaging me.

Even just blocking him wasn't enough

cos I'd see him in school the next day.

Nobody else said anything, but Alex stood up for me.

He had my back.

Alex was the one to be like, "Actually, no, hang on.

"There's no need for this."

And I appreciated that so much.

As high school went on,

we would have spent more and more time together.

We just sort of clicked.

August 2014. So this was the summer after we left school.

I don't know what the fuck he's doing in this photo.

Everyone was in a good headspace,

but here he just looks like he's contemplating everything.

I suppose, like, with anyone, you never really...

You never really know.

It takes a long time to examine a device.

It's a lot of work.

We had to be very methodical.

And my overarching concern was, we have a potential predator here,

and I need to do something to make sure that we get him

off the street, because the longer that he stayed out,

the greater the risk.

DS McINNES: Alex, he'd been released on bail.

I'm waiting for the phone download.

And as I'm waiting, I then start to get information

from the National Centre for Missing and Exploited Children,

a very, very similar report from New Zealand.

I needed to make sure it was the same person, the same offender.

# You never asked about my hands... #

At 12, I was very much, like, a nerd,

the type of kid that would remind the teacher that we had homework.

It was hard making friends.

I was quite sheltered and I was just weird.

Everyone started getting into, like, crushes and relationships,

but I just never experienced anything to do with that.

So, like, I felt pressure to start figuring things out.

So I was at home, 6pm - still light.

PHONE CHIMES A girl, like, added me on Snapchat,

someone my age.

I'm bored, and so I added her back.

It was, like, a little taboo that I was talking to someone online

and it was a little bit exciting.

She wasn't from New Zealand.

I'm connected to someone who doesn't really know me.

I feel like I could have been anyone I kind of wanted to be -

say what you want to say, it's fine.

"Ah! So this is what kids my age do.

"This is how you make some friends, like, with the internet."

PHONE CHIMES

Things got romantic.

I just remember feeling weirded out

but kind of flirted at the same time.

"A girl's interested in me!" It was exciting.

PHONE CHIMES

She sent images first.

Full body shot in a mirror, fully exposed.

I was shocked.

Just like, "What?"

PHONE CHIMES

And then she was just like, "Aw, come on!"

I was nervous about it.

PHONE CHIMES

I just kept thinking, "Well, she shared,

"so it's obviously something she's OK with doing,

"and she's my age and maybe this is OK.

"This is probably fine."

And so I sent a very tame sexual image,

and that's when everything switched.

Suddenly, it was, "Now I've got this one picture.

"I will send these to your friends and family.

"It's going to be everywhere unless you send me more."

PHONE CHIMES

I was just confused and scared.

Kind of like in disbelief.

"What do you mean?" Like, "What are we talking about right now

"and is this really happening?"

I didn't know what else to do but comply.

PHONE CHIMES

I was just, like, sending photo after photo,

and they were just like, "OK, but try this angle, try this pose."

And so I was just slowly adding to their blackmail collection

and it wasn't slowing down.

I felt like it just wasn't going to end.

I was crawled up against my door in my room, crying, just crying.

It was about just... Sorry...

With...

Sorry.

PHONE VIBRATES, CHIMES

A few days later, I'd gotten added by another stranger,

and so I put on my little Snapchat story thing,

"Hey, does anybody know this person?"

A few people messaged me like, "Nah."

But then my cousin messaged them and asked what they wanted.

Ivy didn't know who this person was,

so she asked me if I could see.

I added them...

PHONE VIBRATES, CHIMES

..and that's when they sent me a nude picture of Ivy.

This person told me that if they didn't get any more photos,

then they would distribute it.

She was 12. I was just really scared for Ivy in that moment.

I messaged them and I asked why they were doing this,

but they were just so demanding.

They wanted more photos, more photos,

and they were going to get them.

She called the landline and was like, "They're threatening me.

"What is going on?"

Her being distraught on the phone made me start to cry.

And then my mum came in the room and saw me crying,

and she looked at me, and my mum just said, "Well, what's going on?"

The next day, we took a ride down to the police station.

We had a little bit of information around the profile.

That information suggested that they are overseas.

And we weren't able to progress it any further here in New Zealand...

..but I was able to notify the National Centre for Missing

and Exploited Children and alert them to the issue.

And in 2019, I received a phone call from a guy called Neil

from the police service in Northern Ireland.

I've got the initial one in Scotland and one in New Zealand.

The common thread was the address that the internet was used at.

This has got the potential to go much bigger

than it was at that stage.

This is going to get tricky.

LEE: So when Alex went off to university to do computer science,

we spent hours and hours just sank into online games -

taunting each other, taunting other players we'd met online,

getting into arguments about who got the most kills or whatever,

just complete, utter nonsense.

It was always just us, one on one, late at night.

The world's gone to sleep.

It makes it a lot easier for you to talk to somebody

about things that are bothering you, things that are, you know,

so personal to you that you don't really want to say to everybody.

I'd confide in him.

For years, I've had to think about this and look back on, like,

every little interaction I've had with him,

just racking my head about it.

And I'm sure everybody else that knew him is the same.

Alex never changed the whole entire time.

On Facebook, he looked the exact same, with the same hair for years.

There was something invisible about him...

..just not there.

He just was near, like, a figment of your imagination,

a recluse that was stuck in time.

He could fuckin' hide in the corner of that room

and you still wouldn't notice him, you know?

You just wouldn't have noticed him at all.

I never heard of any dating scenario,

definitely never heard of Alex ever being intimate with anybody.

It was all just online, gaming.

People just excused it as being shy or they had no interest.

We all sort of moved on.

We're getting into, like, dating lives and getting with girls,

going places with them and stuff.

One girl had, like, a small crush on him in high school

but never told him.

Not sure if he even would have reciprocated it in any way.

He never said he fancied anybody or anything like that.

It was just not there for him.

He would hang out with us for the most part,

but it would always go back to gaming for Alex,

it would always go back to being online.

To people outside of our friend group,

he could have seemed like a bit of a loner and a weirdo, but he wasn't.

I think it's very easy to profile what a predator is like,

but he wasn't like that when he was with us.

The person we knew online and the person we knew in real life

were very similar.

Well, we thought he was.

Alex's bedroom, he had big windows,

and we used to climb through them and scare the shit out of him.

He was on his computer and he had his headphones on.

He was raging. You wouldn't be allowed to go near the computer.

I'm definitely literate with technology, you know. I...

I can figure most things out on my own,

but he was on a league above me when it came to it.

Everything was just so natural to him when it came to technology.

I remember one time in the library in the college,

he was able to log into his social media and stuff,

stuff you weren't allowed to do.

At one point, he showed me how to access the dark web.

He was always figuring stuff out with computers.

He was always super interested in it.

I didn't even give it a second thought.

It's not something that would have crossed my mind,

but definitely looking back on it,

you think you know who somebody is and you don't.

DS McINNES: I get a phone call from the cyber support unit,

the people that have got Alex's mobile and the tablets,

and they're like, "Neil, can you come over?"

That's really unusual.

So straight away, I'm like, "Right, OK."

I have never seen a folder structure such as this.

It's...vast.

Very quickly, it's on the screen in front of me.

The Pictures folder.

We found hundreds of separate folders with separate names.

I click into any one of those...

Yeah. ..it contains indecent photographs.

OK.

This is page after page after page after page,

young girls in various states of undress,

doing...all different things to themselves.

How many images and videos and stuff do you think we've actually got?

Our assessment is that they are separate victim folders,

all of which contain a number of first-generation images and videos.

There's a vast, vast number.

Paedophiles across the world share images,

but a first-generation image is a brand-new victim.

The first download shows me

the largest number of first-generation images

to be captured on a device -

certainly within the UK, potentially worldwide.

It's just beyond the realms of kind of like my head space.

It just... It's huge.

OK.

Holy shit.

You know, just one of those, "Wow!"

There's 232,000 first-generation images,

and that's just one device.

I've got to ID all those children.

How am I going to deal with this now?

Where do we even start?

He used my photos to catfish other girls,

and I felt like I had been a part of it now, too.