Internet monster who preyed on 3,500 families across the world: Bedroom lair catfisher Alexander McCartney who blackmailed American 12-year-old girl into killing herself before her dad took his own life is jailed for 20 years

A prolific and deviant catfish abuser who drove a terrified 12-year-old girl to take her own life and left hundreds of others degraded and humiliated was today jailed for life.

Alexander McCartney, 26, showed no emotion as he was told at Belfast Crown Court that he must serve at least 20 years before being considered for release.

The computer science student caused Cimarron Thomas to use her father’s handgun to shoot herself in the head rather than submit to his ‘sadistic’ demands.

Her US army veteran father Ben later took his own life after being consumed with guilt for leaving his gun where his ‘angelic’ daughter could access it.

McCartney, of Newry, South Armagh, had pleaded guilty to the manslaughter of Cimarron at her home in Bruceton Mills, West Virginia, at a hearing earlier this year.

He also admitted 184 other offences of blackmail and inciting a child to engage in sexual activity. 

 Police estimate he ’caused serious and long-lasting harm’ to about 3,500 victims and their families. On one occasion, it took him only nine minutes from meeting a 12-year-old girl for the first time until he had groomed, blackmailed and abused her.

Jailing McCartney today, the judge Mr Justice O’Hara said he had been responsible for the ‘deviant and sadistic’ targeting of young girls for his own sexual gratification.

A mugshot of Alexander McCartney who admitted manslaughter relating to Cimarron’s death

He said he had used social media on an ‘industrial scale’ to pick out his vulnerable victims aged from 10 to 16.

The judge said many had their childhood ruined and families been scared by his remorseless action.

‘I find it hard to think of a sexual deviant who poses more risk than this defendant’, the judge said.

He described McCartney as being ‘devoid of normal human empathy’ who revelled in his ability to degrade and humiliate his young victims.

McCartney sat with his head bowed as the judge took almost an hour to describe the devastation he had caused. He stared at the floor when sentence was passed.

The judge said McCartney had set in motion a devastating series of events involving the Thomas family from just two and half hours of online conversation with the 12-year-old.

He said he had showed her no mercy to her as she pleaded to be left alone and not involve her younger sister in deviant sex acts.

Following the sentencing, her grandparents of Cimarron, Dale and Peggy Thomas, spoke of the void left in their lives.

In horrific messages between Alexander McCartney and one of his child victims, his perverted tactics are laid bare as he can be seen joking and flirting before suddenly turning nasty 

The couple from Frostburg, Maryland, said: ‘We all have been devastated by our Granddaughter’s passing. We know that nothing that we do or say will bring her back.

‘But if we can help another family to not have to go through what we did, something good could come out of her death. Parents, please keep the doors of communication open concerning the evil of some people online.’

US officials described McCartney as ‘detestable’.

Alexander McCartney committed some horrific and disturbing crimes and deserves every minute he serves in prison,’ said Special Agent in Charge Derek W. Gordon, of Homeland Security Investigations (HSI) Washington DC.

‘His wretched conduct tragically led to a child in West Virginia taking her own life. We are thankful that our law enforcement partners in Northern Ireland saw fit to apprehend and charge McCartney for his role in the girl’s death.

‘Their investigation and prosecution of this case were nothing short of brilliant. HSI Washington DC will continue to work with our law enforcement partners, at home and abroad, to ensure that detestable criminal actors like McCartney answer for their transgressions.’

The Northern Ireland Police Service said the investigation into the crimes was one of the most complicated ever undertaken.

Detective Chief Superintendent Eamonn Corrigan from the PSNI’s Crime Operations Department said: ‘My team and I welcome today’s sentencing. Investigating Detectives have been determined to bring McCartney before the courts to answer for his crimes and today we have done just that.

Cimarron Thomas (left) with her US army veteran father Ben Thomas, who later took his own life after being consumed with guilt for leaving his gun where his daughter could access it

‘McCartney is nothing but a disgusting child predator who was posing as young girls online to groom, manipulate and sexually abuse his victims, as young as four, to satisfy his own sexual perversions and that of other online child sexual offenders.

‘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.

‘Sitting in his childhood bedroom in Newry, he began his offending as a late teenager and built what can only be described as a paedophile enterprise. He had a number of devices and was operating across different time zones.

‘He has caused serious and long-lasting harm on what we estimate to be around 3,500 victims and their families. I want to thank those who have come forward today for being so incredibly brave and assisting our investigations.

‘As far as I am concerned there is only one place for McCartney and that is behind bars. I am glad his offending has been uncovered and that it has today been taken seriously by our criminal justice system.

The former University of Ulster student had pretended to be a teenage girl when contacting hundreds of other young girls, many who were gay or unsure of their sexuality.

Alexander McCartney (pictured), 26, operated from the bedroom of his family home in rural Northern Ireland and persuaded young girls to send naked pictures of themselves

Cimarron and Ben Thomas with mother Stephanie. The double tragedy ripped apart the family

Cimarron Thomas (pictured) was subject to sick blackmailing online by McCartney and used her father’s handgun to take her own life 

Using the Snapchat and other social media he persuaded them to send topless photos – before revealing they had been catfished.

Catfishing involves the use of a false identity online to befriend and exploit victims.

He had first made contact with Cimarron Thomas in May 2018. After receiving intimate photos he tried to blackmail her into carrying out his deviant demands.

Despite tearfully pleading with him to stop McCartney threatened to send the photos to her father and friends.

When she refused his demands and said she would shoot herself he cruelly began a countdown and told her ‘goodbye and good luck.’

The youngster was found dying by her nine-year-old sister.

Police who carried out the investigation into McCartney today released the emergency call made by a neighbour who has rushed to help the young girl.

Much of the call is muffled, but the 911 operator can be heard telling the neighbour to apply pressure to the head wound.

Cimarron’s 40-year-old father Ben took his own life 18 months after her death.

Cimarron (pictured with her father Ben) was told that if she did not comply with McCartney’s requests, her photos would be sent to her father

Cimarron’s mother Stephanie (pictured left) still struggles to deal with the loss of her husband and daughter six years after the double tragedy – she is pictured here with Cimarron 

The Thomas family initially had no idea why their daughter (pictured) had taken her life and were unaware of the depravity she had been subjected to

At the time the family from a rural town had no idea why Cimarron had committed suicide.

It was only in 2021 when police found a transcript of the conversation between Cimarron and McCartney they were able to tell them the reason for her death.

He had kept the online chat as a ‘trophy’ on his computer.

Family members told MailOnline that McCartney ‘might as well pulled the trigger’ and were outraged that he was not charged with murder.

They had hoped that he would be extradited to the US, but State Department authorities say that will not happen.

Members of the Thomas family said the double tragedy had torn apart their family with Cimarron’s mother Stephanie suffering from PTSD and six years on unable to bring herself to talk about her daughter’s death.

Prosecutor David McDowell spent 90 minutes describing how McCartney had ‘degraded and humiliated’ his victims and showed no mercy when they pleaded with him to stop.

McCartney refused to listen to the gut wrenching details of his campaign of abuse, sitting in the dock with his head bowed and hands covering his ears.

Most of his victims were aged from between 10 and 16 and lived in the UK, Europe, America, Australia and New Zealand.

Pretending to be a girl, McCartney found and befriended girls who were said to be struggling with sexuality.

His lawyers said McCartney had showed genuine remorse and has been held on remand for five years since being arrested in 2019.

McCartney used his technical knowledge as a computer science student to carry out his crimes, said the prosecution

Cimarron Thomas, 12, (pictured) used her father’s handgun to take her own life after being blackmailed online by McCartney

A tribute to Cimarron Thomas, 12, (pictured in the frame centre) who took her own life

He flattered them to get a compromising photograph and then used it to blackmail and threaten the teens into committing appalling acts.

Each victim was left terrified that their intimate photos would be exposed to family and friends.

McCartney told one girl that he would get people to come to her house to rape her if she didn’t comply.

When another said her mother was dying of cancer he said:’ I don’t care’ and continued with his relentless abuse.

Prosecutors said he carried out the abuse for his own sexual gratification.

It only came to an end after a girl in Scotland complained that she was a victim of catfishing and the UK’s biggest catfishing investigation was launched.

In March 2019 police in Scotland contacted their counterparts in Northern Ireland about a 13 year old girl who had been groomed by an adult using the alias of someone her age.

McCartney was traced and arrested. Pollice seized 64 devices and found tens of thousands of images of underage girls performing sex acts while being blackmailed.

His lawyers said McCartney had showed genuine remorse and has been held on remand for five years since being arrested in 2019.