A 26-year-old man from Northern Ireland who pretended to be a teenage girl on the internet to target thousands of girls in a wide-reaching online pedophilia case and who was convicted of manslaughter in the death of a 12-year-old girl in the United States was sentenced in Britain on Friday to at least 20 years in prison.
Alexander McCartney pleaded guilty to 185 charges of child sexual abuse crimes and blackmail. He had pleaded guilty to the manslaughter charge in March.
“This was one of the most depraved, distressing and prolific cases of child sexual abuse that we have ever seen in the public prosecution service,” said Catherine Kierans, the acting head of the Serious Crime Unit of the Northern Ireland Public Prosecution Service, during a news conference on Friday.
Pretending to be a teenage girl, Mr. McCartney, 26, lured his victims into a false sense of security. He urged them to send explicit photos or engage in sexual activity via a webcam or a cellphone and later blackmailed them, according to the Police Service of Northern Ireland. Mr. McCartney then spread those images and videos around the internet, they said.
Mr. McCartney groomed, manipulated and sexually abused his young victims, Detective Chief Superintendent Eamonn Corrigan said in a statement. Mr. McCartney started his deception of girls online from his childhood bedroom in Newry, a city in Northern Ireland, when he was in his late teens.
The Northern Irish police estimated that Mr. McCartney had about 3,500 victims in multiple countries.
He built “what can only be described as a pedophile enterprise. He had a number of devices and was operating across different time zones,” Mr. Corrigan said.
In 2018, Mr. McCartney’s operation led to the death of Cimarron Thomas, a 12-year-old girl in West Virginia. Cimarron shot herself during online contact with Mr. McCartney, according to the Northern Irish police, “the catalyst being that he was attempting to coerce her into involving her younger sibling.”
On Friday, Mr. McCartney became the first person in the United Kingdom to be sentenced in the manslaughter of a victim who was living in a foreign country.
In New Zealand, the father of two of young girls who fell victim to Mr. McCartney told the P.A. news agency in Britain that Mr. McCartney had befriended his oldest daughter on the social media platform Snapchat in 2017. After gaining her trust by pretending to be a girl like her, Mr. McCartney had her pose nude.
“Once he had that, he had the power and it was a case of playing by his rules,” the father, who was only identified by the name Bob, told the P.A. Later, Mr. McCartney also asked for pictures of the girl’s younger sister, he added.
The police in Northern Ireland initially found out about Mr. McCartney when they received a report in 2019 from police officers in Scotland about a 13-year-old girl who was being groomed by an online predator.
When detectives identified Mr. McCartney’s home that year, they arrested him and seized 64 devices that held tens of thousands of photos and videos of underage girls performing sexual acts as they were being blackmailed through his multiple fake online accounts, including on Snapchat.
Extortion of minors on the internet is also a major problem in the United States. According to the website of the Federal Bureau of Investigation, the online extortion of children and teenagers who are coerced into sending sexually explicit images has seen “a huge increase.” The same is true for what the F.B.I. calls “financial sextortion,” which involves predators threatening to release the sexually explicit images unless they receive payment.
From October 2021 to March 2023, more than 13,000 instances of financial sextortion of minors were reported to the F.B.I. and Homeland Security Investigations, involving at least 12,600 victims, most of them boys.
Officials have ramped up their efforts to crack down on sextortion schemes, which overwhelmingly target minors. From January 2021 to July 2023, at least 20 teenagers killed themselves after being caught in such a scam, according to the F.B.I.
The devastating consequences have prompted officials and victim advocates to undertake awareness campaigns to teach teenagers how to protect themselves and emphasize that help is available if they have been victimized.
Mr. McCartney will be eligible for parole no sooner than 2039, when the parole board will be able to review his case. Mr. McCartney has been in custody since 2019.
