How a brave Scottish teenager held key to catching online global 'catfish' predator

One of the world's most prolific online child abusers has been given a life sentence with a minimum of 20 years in jail for the extreme online sexual abuse of children and the manslaughter of a 12-year-old girl.

In what has been described as a “horrific” case that only came to light after Police Scotland received a report of a 13 year-old Scottish girl being groomed, Alexander McCartney admitted a total of 185 charges, including more than 50 blackmail offences, inciting a child to engage in sexual activity, and producing and distributing indecent images of children.

Although the charges against the 26 year-old focused on 70 children, the Police Service of Northern Ireland (PSNI) and the Public Prosecution Service for Northern Ireland (PPS) believe he targeted as many as 3,500 youngsters while posing as a young girl to lure his victims into sending intimate images.

Catherine Kierans, acting head of the serious crime unit at the PPS, told The Scotsman the brave decision of the Scottish child to speak out helped prevent other young girls from being targeted by McCartney. “That was absolutely critical to the case and she probably saved other victims,” she said.

Once in receipt of photographs from his victims, McCartney would blackmail them for more extreme images, warning them he would expose them to his friends and family. He forced some of the children to involve their younger siblings in the abuse, as well as family pets.

His victims included Cimarron Thomas, a 12 year-old from West Virginia in the US. He repeatedly contacted her to obtain images, but when McCartney told her to include her little sister in his campaign of abuse, Cimarron took her own life instead of complying with his depraved request. Her body was found by her younger sister, and just 18 months later, Cimarron’s heartbroken father, Ben, took his own life.

At a sentencing hearing at Belfast Crown Court on Friday, Mr Justice O'Hara said it was difficult to think of a "sexual deviant” who posed a greater risk than McCartney.

“To my knowledge, there has not been a case such as the present where a defendant has used social media on an industrial scale to inflict such terrible and catastrophic damage on young girls up to and including the death of a 12-year-old girl,” he said.

“The defendant was remorseless. He ignored multiple opportunities to stop. He ignored multiple pleas for mercy. He lied and lied and then lied again.”

The global trail of victims devastated by McCartney’s crimes only emerged after a referral from police in Scotland. Although McCartney first became known to Northern Irish police in 2016, when he was arrested in relation to indecent images of children found on his electronic devices, no victims had been identified at that time, and he was bailed.

He was arrested again on similar offences in 2018, and despite the attention of police and bail conditions, continued to offend, replacing phones and laptops which had been seized by authorities.

The situation quickly escalated in March 2019, when Police Scotland received a report of a 13 year-old girl being groomed by an adult suspect believed to be residing in Northern Ireland. McCartney had posed as a 13 year-old girl himself in order to “catfish” his victim.

That development, Ms Kierans said, was integral to the case against McCartney. “It was a Scottish child who was the first to raise the alarm,” she said. “That really made police look at it again, because they weren’t aware of the offending he was doing online in terms of contact with young girls. That led to the final arrest.

“If that Scottish child had not spoken up, it might have taken longer because the police were still examining the devices, they were still in a queue, but her report brought everything to the fore.”

Indeed, when the PSNI raided McCartney’s home after being contacted by Police Scotland, they discovered him in the middle of offending, with Snapchat - the app he used to contact his victims while posing as a young girl - open on one of his mobile phones. A total of 64 devices were seized from his home, and found to contain tens of thousands of photos and videos of underage girls performing sexual acts whilst being blackmailed.

Detectives soon realised that McCartney's offending had spread not just across the UK, but around the world. Working with colleagues in the US Homeland Security and the National Crime Agency, victims were located in the US, Australia , New Zealand and at least 28 other countries.

Ms Kierans said some of McCartney's victims had never been identified, despite exhaustive efforts by investigators.

“McCartney's crimes have harmed thousands of children and left them and their families dealing with the traumatic aftermath," she said. “Their courage stands in stark contrast to his cowardice in targeting vulnerable young girls.

“All McCartney’s victims were young, innocent children. Some of the estimated 3,500 girls he targeted, who were as young as ten, were already struggling with identity and body image issues and had reached out for help on social media. He sought to exploit that vulnerability in the most shocking ways. Some children pleaded for him to stop the abuse, but he callously continued, at times forcing the victims to involve younger children, some aged just four.”

The PSNI said McCartney’s offending was so prolific that on one harrowing occasion, it took him a mere nine minutes to groom, sexually abuse, and blackmail a girl aged 12.

Detective Chief Superintendent Eamonn Corrigan said: "We have worked tirelessly around the clock on this case, with international criminal justice partners to safeguard victims and build a robust case against this man whose offending has shocked communities around the world.”