A “prolific and chilling” sex abuser from Northern Ireland has been sentenced to 27 years in prison.

David John Andrews, 55, with an address at Maghaberry Prison, pleaded guilty to 130 charges of sexual abuse.

The charges – including attempted rape, threats to kill and inciting children to engage in sexual activity – relate to 47 victims, 46 of whom were children at the time of the offences.

Many of Andrews’ victims were from England.

The judge told the court that much of the detail of the offending was “too harrowing and vile to be repeated”.

Andrews must serve a minimum of 13 and a half years before he is eligible for parole.

Downpatrick Crown Court was told his youngest victim was eight years old and that the attempted rape charges relate to a young woman who was profoundly disabled.

Many of the charges relate to catfishing – he regularly posed as a young boy and blackmailed children to engage in sexual activity.

Threats of violence were common and he sometimes offered children money for images.

He used images of some of his victims in exchange for other illegal and pornographic images.

He also pleaded guilty to attempting to arrange child prostitution

Many of the charges are from 2019 and 2020. Andrews has been on remand for more than four years.

Andrews defence barrister told the court he had complex mental health issues and had been self-medicating with cocaine at the time of the offending.

The judge said Andrews was “calculated and determined” in his offending and the graphic details of the case show the “depths of depravity” involved.

One of his victims has spoken to the BBC about her experiences with Andrews.

Claire, not her real name, was 13 when Andrews catfished her on Instagram and groomed her, she believed he too was 13.

“At first it was a friendly conversation and then it got more threatening to send photos, and in the end I did send them,” Claire said.

“He would threaten my friends and became very aggressive. Things got worse as soon as I sent them, he was asking for them near enough every day, and I was sending them,” she said.

When Claire stopped sending pictures to Andrews he threatened her, promising he would share the images with her friends and school.

“He went through my list of followers from my school and friends, and he sent them to those people. The photos were then sent all around school,” she said.

“It destroyed me, I left school for several months and I never went back fully. I was suicidal, self-harming every day. It closed in on me a lot, it destroyed a lot of my family bonds, I lost almost all my friends. I blamed myself.”

Claire’s mum has also spoken to the BBC about the crimes against her daughter.

“It makes you feel like you’ve failed as a parent. She was in her bedroom scared and sending these pictures because he was threatening her and I knew nothing, if I’d know I could have stepped in,” she said.

“After it all came out we had to set alarms in the night to make sure she hadn’t done anything to herself. She just blamed and blamed herself.”

Claire says that the repercussions from Andrews’ actions stayed with her for years.

“No one could help me, I was too far in my own head, I didn’t want the help, I thought I deserved what had happened to me,” Claire said.

She’s waited over four years for Andrews to be sentenced: “It’s been a long and tortuous process getting the case to court. I feel like I’ve been locked away. I can’t go out like a normal kid and have fun. I’m constantly waiting for the next phone call to say what’s happening,” she said.

“I hope I can finally close a lid on this part of my life. I’m still not mentally stable, I don’t think I ever will be. I was ashamed but in the end it’s not your fault, you’re a victim. It took ages for me to think it wasn’t my fault.”

Claire’s mum has a simple message for other parents.

“As a parent this has been devastating. She’ll build a life but this will always be there in the background.

“To other parents I can only say, check their devices, and if your child comes forward to tell you something believe every word they say, some people wouldn’t have believed this story, but every word turned out to be true.”

The head of the Public Prosecution Service (PPS) serious crime unit, Catherine Kierans, described Andrews as a “dangerous and devious paedophile”.

“His actions caused great fear, distress, and trauma to the victims, some of whom bravely raised the alarm, ultimately leading to the outcome today,” she said.

“I want to pay tribute to the courage of his victims, including those who were prepared to face Andrews down by giving evidence in court, had he not pleaded guilty.”

Ms Kierans warned all those who care for children and young people to be vigilant of the dangers posed by online predators.

“If you think you are being targeted in this way, you are not alone, and you are not to blame. Please reach out and speak to a trusted adult,” she said.

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

The ‘catfish’ is the person who has created the fake persona.

They target people through social media and messaging apps, usually for abuse and fraud.

Speaking at a press conference, Det Ch Insp Jill Duffie described Andrews as a “vile predator” who committed “heinous crimes”.

“Let today’s sentence serve as a warning to those operating online and hiding behind fake accounts and firewalls.

“You will be caught, and you will face the full force of the law when you are.”

“These sentences and these huge cases coming to the court should reassure people that there is no hiding place for this type of offender,” she added.

DCI Duffie said her team conducts searches and arrests on “a weekly, if not daily, basis for this exact type of behaviour”.

“We work with all the law enforcement across the UK. We get intelligence on a daily basis,” she stated.

“Practically every child and young person across the UK has access to a smartphone.

“We, along with other police forces, are seeing an increase in this type of offending.

“So we would appeal to anyone who feels they have been a victim of Andrews or of anyone else to come forward and report it to police,” she added.

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