‘Catfish killer used my photo to trap other girls’

Alexander McCartney is one of the world’s most prolific online sex offenders

Warning: This story contains distressing details relating to extreme child abuse and suicide.

A teenager blackmailed into sending explicit images to catfish killer Alexander McCartney has told of her anger that he used her photograph to trap other young girls.

Emily (not her real name) was targeted by McCartney in 2018.

At the time she was 14 and living in Oregon, in the US.

"I had sent nude photos with my face in them," she said.

"That’s how it started."

McCartney, one of the world’s most prolific online sex offenders, was jailed for at least 20 years in October.

Emily is among three of his young victims to have spoken to the makers of a BBC Three documentary Teen Predator/Online Killer.

McCartney pleaded guilty to a litany of child sex offences and the manslaughter of 12-year-old Cimarron Thomas, who took her own life minutes after an online chat with him in 2018.

More than 3,500 victims were identified in Belgium, Canada, Croatia, Colombia, Denmark, Germany, Italy, Latvia, Lithuania, Mexico, the Netherlands, Norway, New Zealand, Poland, Slovakia, Spain, Sweden and the US as well as the UK.

McCartney, who is from Northern Ireland, posed as a teenage girl called Chloe to trick Emily and others into sending photographs.

He would then use a pre-typed message to reveal himself as an online predator.

"My heart dropped out of my chest," said Emily.

"And I just felt my whole world collapsing around me. It was very scary."

Cimarron Thomas, 12, lived in West Virginia but was abused by McCartney from a room in Northern Ireland

Despite the scale and breadth of McCartney’s offending only four children went to the police.

Emily did not tell anyone about her abuse until she was contacted by US Homeland Security in 2021.

"It tore some of my innocence out sending those photos," she added.

Teen Predator/Online Killer

How does a Northern Irish teen become one of the world's worst online child sex abusers? Victims, families and police share how Alexander McCartney was caught.

Teen Predator/Online Killer is a co-commission for BBC Northern Ireland and BBC Three by DoubleBand Films - watch now on BBC iPlayer.

She also felt trapped, paranoid and was living in fear of encountering "Chloe" face-to-face.

"I don’t remember the timeline. I just remember it ended," she said.

"I never knew if they’d contact me again or if they knew where I lived."

McCartney created a profile on Snapchat using Emily’s picture.

"He used my image to catfish other girls. And that does make me angry," she said.

'Beyond the realms of my head space'

Exclusive footage from McCartney’s police interviews has also been made public for the first time.

It shows him slumped over the desk and with his head in his hands - a stance he also adopted during recent court proceedings.

He replied "no comment" to almost all questions.

Det Sgt Neil McInnes of the Police Service of Northern Ireland (PSNI), who led the investigation, revealed how McCartney’s phones and computers contained "page after page" of photographs showing young girls in various states of undress "doing all different things to themselves".

Some 232,000 images were found on just one device.

"The first download shows me the largest number of first generation images to be captured on a device, certainly within the UK, potentially worldwide," he said.

"It’s beyond the realms of my head space. It’s huge."

Neil McInnes led the investigation

The documentary details how the PSNI worked with law enforcement agencies abroad to bring McCartney to justice.

"Ivy", from Hawke’s Bay in New Zealand, told police there what had happened after her cousin came to her aid.

She told the documentary-makers how McCartney entrapped her when she was 12 and at a vulnerable point in her life.

"I was very much a nerd," she explained.

"The type of kid that would remind the teacher we had homework. It was hard making friends.

“Everyone had started getting into crushes and relationships but I had never experienced anything to do with that. So I felt pressured to start figuring things out.

"A girl added me on Snapchat - someone my age."

She described how she felt "weirded out and flattered at the same time".

After receiving pictures, she sent "a very tame sexual image, and that’s when everything switched".

When McCartney began to blackmail her, she was "confused and scared and in disbelief" and "didn’t know what else to do but comply".

'Bit of a loner and a weirdo'

McCartney began committing his crimes when he was a teenager at school, and continued when he went to university to study computer science.

One of McCartney’s former friends, Lee, recounted how McCartney was "super-interested" in computers and "always figuring stuff out".

"I didn’t give it a second thought. But definitely, looking back at it - you think you know who somebody is, and you don’t," he said.

"To people outside our friendship group, he could have been seen as a bit of a loner and a weirdo.

"It’s very easy to profile what a predator is like. But he wasn’t like that when he was with us."

Lee said the shock of learning what McCartney had done has had a profound effect on him.

He said he looked back "at every little interaction I had with him, racking my head about it".

"I’m sure everybody else who knew him has done the same," he added.

"I hate everything about this situation. It’s a nightmare to think about and I’m just glad nobody else is going to get hurt."

Detectives, prosecutors and victims told the documentary-makers how important it was that anyone suffering online abuse should feel able to report it.

"Violet", from Virginia Beach in the US, came forward to a police officer based in her school.

She said she thought that catfishing was "such a light term for this situation".

"To me, being catfished means you are on a Tinder profile and your pictures look different to what you look like in real life," she said.

"That is not what this was. I reported him (McCartney) and he got caught."

She wanted to encourage other victims to speak out "because you never know the magnitude of what you are dealing with".

Ivy, from New Zealand, said: "There are definitely too many girls who have been through something similar to what I have been through and have just never spoken up.

"Talking about it definitely helps.

"I like who I am nowadays."

Teen Predator/Online killer is available on BBC iPlayer. It is a co-commission for BBC Northern Ireland and BBC Three by DoubleBand Films.

If you have been affected by the issues raised in this story you can visit the BBC Action Line for support.