Geoffrey Muir jailed for grooming and sexually abusing little girls after meeting his mother on Tinder

WARNING: This story concerns child sexual abuse. Help and crisis information can be found below.

When she met Geoffrey Muir on Tinder, she never imagined that within two years he would destroy her family – abusing and raping her older daughter until her twelfth birthday and then moving on to her five-year-old daughter.

The girls were entrusted to Muir. He was charming. She thought he was a good man.

But now she knows he is a monster – a cunning predator, a manipulator, a sick child sex offender.

And she fears there are more victims.

In early 2020, the woman met Muir, then 53, through the dating app Tinder.

The two became friends and Muir spent a lot of time in the house she shared with her young daughters.

After all, he had access to the girls almost every day and was trusted to be alone with them.

No one had any idea what he was doing to the children until the older girl revealed Muir’s abuse in 2023, fearing he would do the same to her little sister.

It was too late.

The woman went to police in 2023 and Muir was charged with 12 counts of sexual abuse against the older girl, ranging from indecent behavior to rape and exposing the woman to pornography.

He was accused of two counts of sexual abuse of the younger girl.

Two further charges were brought against Muir for producing or possessing indecent material, including images and videos of the sisters.

Muir was arrested and charged in Tauranga, where he was living at the time.

The crime occurred elsewhere in New Zealand.

He pleaded guilty to most of the charges at his first appearance in the Tauranga District Court. At sentencing on Monday, he pleaded guilty to the remaining charges and several new charges.

Muir’s list of crimes was laid out in a 12-page summary of facts provided to the Herald was provided.

In November 2021, he began sexually abusing the older of the two girls, who was ten years old at the time.

“During this time, (Muir) took every opportunity to sexually abuse (the girl), with increasing frequency until the abuse became normal and expected – with measured severity, from touching and rubbing of the genitals to sexual violence,” the summary states.

“To avoid discovery of his crimes, the abuse took place in (the girl’s) bedroom at night; in her mother’s bedroom when no one else was home and windows, curtains and doors were closed… and in the privacy of his truck after he had bribed (the girl) to travel with him as a passenger.

“The sexual abuse (of the older girl) ended in 2021, before her 12th birthday.”

Muir then began abusing the younger girl, who was just five years old.

“(He) was tactful and calculated in his attempt to sexually abuse (the little girl) and always made sure that she kept the abuse secret.

The Herald No specific details of the individual charges were published – most of them were representative, meaning they involved several similar crimes that could not be traced back to a specific date.

Muir’s assaults against the older girl steadily escalated, becoming increasingly more intrusive.

He gave her a sex toy and encouraged her to use it and then hide it under her pillow.

“It’s fun to be naughty, isn’t it?” he said to her during an assault in which he used the toy.

He began bribing the girl to go with him to the supermarket and other places by giving her $20 at least once and promising to buy her chocolate.

“(Muir) used this tactic to lure her into his truck with the sole purpose of having time and privacy to sexually assault her,” police said.

“Typically, (Muir) would give her his phone before or after he touched her in her bedroom. He would instruct and encourage her to use his phone solely for viewing pornography on Pornhub.

“This happened with such regularity that (the girl) could no longer count how many times it happened.”

According to police, Muir’s sole purpose in encouraging the girl to watch pornography was to “sexualize her behavior with the express intent of inducing her to participate in the sexual activities” she was subjected to.

Shortly after the girl turned twelve, Muir’s abuse stopped.

The only reason for this was that he had focused his attention on her younger sister, police said.

“The defendant used the time he spent playing with (the girl) to sexually abuse her,” police said.

“When we were alone, (Muir) would playfully let (the five-year-old) catch him looking at pornography on his phone as if it were a game,” police said.

“He then had her watch pornography on his phone. He knew that this would pique her interest enough to want to see more… watching pornography was closely linked to the sexual abuse.”

Muir also made explicit videos with the girls and took photographs – mostly in their mother’s bedroom.

When Muir learned that the girls’ mother was going to the police, he went to the Tauranga police station with a lawyer and made a full confession.

“He admitted … that he had (the girls) watch pornography on his cell phone in order to manipulate the situation into committing sexual offenses,” police said.

“He found it exciting.”

Sentencing Muir was handed down by Judge Paul Geoghegan, who opened the proceedings by asking the girls’ mother to read a victim impact statement.

The woman said her older daughter only came forward because she feared Muir would abuse her little sister.

“These fears were well-founded,” she said.

She said Muir was “sick” and “monstrous” and had “manipulated, groomed and used” her for years – all to get to her little girls.

“The wounds are not physical, but they are deep and real and personal,” she said.

“He took something so precious from me – the innocence of my children… their ability to grow up without trauma.

“As a mother, I am devastated. I have failed to protect my children from a monster hiding right under our noses… I am living every parent’s worst nightmare.

“It’s absolutely heartbreaking… This is a life sentence, a burden that we have to bear… I can’t take away their memories… I can only tell them that what happened is not their fault.”

She said Muir was a “cunning predator” who hid behind his “charm.”

“I firmly believe that my children are not his first victims,” she said.

“I have absolutely no doubt that he will relapse when he is free. He doesn’t deserve to be free if we will never be free.”

A pre-sentence report said Muir posed a high risk of harm to other children and there was “serious potential” for him to commit similar offences in the future if given the opportunity.

Muir said he was an alcoholic but had been sober for 14 years.

He suspected that he had not “fully addressed the underlying issues” of his addiction and had merely “shifted” it from alcohol to sex.

“You stated that you did not do it intentionally – it just happened,” Judge Geoghegan said.

“Even if you did not intend it at first, your conduct has all the hallmarks of a calculated and predatory crime.

“There was planning and premeditation… You took every opportunity to be with them, you maintained secrecy with them, you regularly exposed both of you to pornography to normalise and encourage sexual behaviour.

“There was a high degree of manipulation … for personal sexual gratification. This will haunt the victims and their mothers forever.”

Judge Geoghegan sentenced Muir to 12 years and nine months and ordered that he serve half of that time before being eligible for parole.

“The significant risk you pose to the daughters of all persons with whom you have a relationship and the fact that your charm and manipulation increase that risk … justifies a minimum term without parole,” he said.

“What I want to say to the victims and their mother – and this may be little or no consolation – is that they have no reason to feel guilty.

“There is one person, and one person only, responsible for us being here today – and that person is you, Mr. Muir.

“The victims were manipulated by you to satisfy your perceived needs… a conviction cannot possibly heal the damage done to this family.”

Anna Leask is a Christchurch-based reporter covering national crime and justice. She joined the Herald in 2008 and has worked as a journalist for 18 years, with a particular focus on family violence, child abuse, sexual violence, murder, mental health and youth crime. She writes, hosts and produces the award-winning podcast A Moment In Crime, broadcast monthly on nzherald.co.nz