Geoffrey Muir is in prison for grooming and sexually abusing little girls after meeting his mother on Tinder

WARNING: This story involves child sexual abuse. For help and crisis information, see below.

When she met Geoffrey Muir on Tinder, she never imagined that within two years he would have destroyed her family by abusing and raping her eldest daughter until her 12th birthday, then turning his attention to her five-year-old.

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

But now she knows he’s a monster: a cunning predator, a manipulator, a sick child molester.

And she fears there are more victims.

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

The pair ended up as friends and Muir spent a lot of time in the home she shared with her young daughters.

Eventually he had access to the girls almost every day and was allowed to be alone with them.

No one had any idea what he was exposing the children to 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 offenses against the older girl, ranging from committing indecent acts to rape and exposing her to pornography.

He was charged with two counts of sexually assaulting the younger girl.

A further two charges were laid in relation to Muir making or possessing objectionable material, including images and videos of the sisters.

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

The crime took place elsewhere in New Zealand.

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

Muir’s litany of insults was laid out in a twelve-page summary of the facts, which… Herald was provided.

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

“During this period, Muir took every opportunity to sexually abuse the girl with increasing frequency, to the point where the abuse became normalized and expected – with measured severity, from genital touching and rubbing to sexual violation,” the summary said.

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

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

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

“(He) was tactful and calculated in his pursuit of sexually abusing (the little girl) and continually ensured that she would keep the abuse as their secret.

The Herald has chosen not to publish the specific details of each charge – most of which were representative, meaning there were multiple offenses of the same type that could not be pinned to a specific date.

Muir’s transgressions against the older girl steadily escalated, with even more intrusive transgressions.

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 a fit using the toy.

He began bribing the girl to, among other things, go with him to the supermarket, saying he would buy her chocolate and give her $20 at least once.

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

“Normally, before or after touching (her) in her bedroom, (Muir) would give her his cell phone. He instructed and encouraged her to use his cell phone solely to view pornography on Pornhub.

“This happened so regularly that the girl lost count of the number of times it happened.”

Police said Muir’s sole purpose in encouraging the girl to watch porn was to “sexualize her behavior for the express purpose of engaging her in the sexual activity” to which she was exposed.

Just after the girl turned 12, Muir’s abuse stopped.

Police said the only reason for this was because he had “focused his attention” on her younger sister.

“The suspect used the moments when he played with (the girl) to sexually abuse her,” police said.

“While … alone together, (Muir) playfully caught (the 5-year-old) watching pornography on his cell phone as if it was a game,” police said.

“He then made her watch pornography on his cell phone. He knew this piqued her interest to the point where she asked to see more…viewing pornography was intertwined with sexual abuse.”

Muir also filmed lewd videos involving the girls and took photographs – usually in their mother’s bedroom.

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

“He admitted to making (the girls) watch pornography on his cell phone to manipulate the situation that would lead to sex crimes,” police said.

“He found this exciting.”

Muir was sentenced by Judge Paul Geoghegan, who began the proceedings by inviting the girls’ mother to read a Victim Impact Statement.

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

“That fear was 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 run deep and are real and personal,” she said.

“He took something so precious: my children’s innocence… their ability to grow up without trauma.

“As a mother I am broken. I failed to protect my children from a monster hiding in plain sight… I’m living every parent’s worst nightmare.

“It’s completely heartbreaking… This is a life sentence, a burden of damage that we will have to go through… I can’t take away the 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 reoffend when he is released. He doesn’t deserve to be free, while we never will be.”

A report said there was a high risk of Muir harming further children, and that there was a “serious potential” for him to commit similar crimes if given the chance in the future.

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

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

“You said you didn’t plan it – it just happened,” Judge Geoghegan said.

“Although you may not initially intend it, your behavior shows all the hallmarks of calculated and predatory offending.

“There was planning and premeditation… you took every opportunity to be with them, you maintained secrecy with them, you regularly exposed porn with the intention of normalizing and encouraging sexual behavior.

“There was a high degree of manipulation… for your own sexual gratification. It will be with the victims forever, and with their mother.”

Judge Geoghegan sentenced Muir to 12 years and nine months and ordered him to serve half before being eligible for parole.

“The significant risk you pose to the female children of anyone with whom you have a relationship, and the fact that your charm and manipulation increases that risk…justifies a minimum period of non-parole,” he said.

“What I want to say to the victims and their mothers – and this may offer little or no comfort – is that they have nothing to feel guilty about.

“There is one person, and one person is solely responsible for why we are here today – and that person is you, Mr. Muir.

“The victims were manipulated by you into your desire to meet your perceived needs…conviction cannot possibly repair 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, focusing on domestic violence, child abuse, sexual violence, murders, mental health and youth crime. She writes, presents and produces the award-winning podcast A Moment In Crime, released monthly nzherald.co.nz