On June 17, 1970 Harvey and Jeanette Crewe were gunned down in the living room of their Pukekawa farmhouse and dumped into the nearby Waikato River.
Fifty years on, theories still swirl around the whodunnit, which has been the subject of two trials, a Royal Commission of Inquiry and a major police review following the conviction and pardon of accused murderer Arthur Allan Thomas. Anna Leask revisits one of our most enduring cold cases.
It was about 1pm when Lenard Demler walked in the back door of his daughter Jeanette's house on June 22, 1970.
He made his way up the passage, turned left into the kitchen and walked through the open sliding doors to the lounge.
There was no sign of his daughter or her husband Harvey.
But there was blood - pools and splatters and dragmarks in various places.
Demler could hear his 18-month-old granddaughter Rochelle calling out and raced into her bedroom, to find her lying down in her cot.
The toddler was not crying or upset - but she was filthy.
Her cot reeked of urine and excrement and she clearly not been cared for for quite some time.
Demler, strangely, left Rochelle in the cot and drove to his own house, where he called a transport company to cancel a stock transfer, saying Harvey was not home.
He then drove to his neighbour Owen Priest's home.
"There is blood all over the place and I cannot find them anywhere," Demler said.
He asked Priest to come back with him to the bloody crime scene, where he lifted Rochelle from her cot and took her to the home of a friend.
By then, the little girl was cold and crying.
Her eyes were bloodshot, sunken in their sockets and her lips and mouth were very dry.
It was only then, an hour and 20 minutes after Demler first went to Jeanette and Harvey's place, a call was made to the Tuakau police.
So began a 50-year-old murder mystery that would see charges laid, evidence planted, convictions quashed and reviews into the police handling of the case.
There have been a number of suspects over the years - including Demler, his other daughter Heather, other local farmers, other members of the Thomas family - but no other arrests.
Many central to the investigation have died and those closest to it are not fond of revisiting it.
Pukekawa farmer Arthur Allan, who was convicted of the murders at two trials and spent almost 10 years in prison before he received a pardon, isn't keen on speaking about the case these days.
He has discussed it when needed, but is now "pretty private" and tries to keep out of the spotlight when it comes to this case.
Rochelle Crewe - now 51 - feels the same about speaking publicly aroudn the anniversary.
The murder of her parents is not something she wants to dwell on.
Thomas' brother Des has spent much of his life fighting to clear his family's name and has vowed to keep "fighting" until he gets answers - and vidication.
But he said this milestone anniversary was more about the death of a young couple.
"We need answers. All we want and require is to take the 'who' out of whodunnit'," he said.
"But at the end of the day, this is about the brutal murder of two people in their own home, who were then chucked in the Waikato River like they were just some dead farm animals.
"That's bloody disgusting."
It was evident from the outset that something terrible had happened in the Crewe house.
Blood and bodily fluids stained the chair where Harvey, 28, usually sat and pooled on the carpet beneath and there was a long drag mark down the middle of the living room floor.
The was also blood on the brickwork near the front steps and in the kitchen - on the linoleum floor, the cupboard doors, the hot water tap, on two saucepans.
Police knew they were looking at a homicide -but, with no trace of Harvey or Jeanette, it was hard to say whether it was a murder suicide, home invasion or something else.
Despite extensive searches of the Crewe property and over large areas of surrounding farmland there was no sign of the couple.
Then, almost a month to the day the bloody scene was discovered, two whitebaiters chanced upon Jeanette's body floating in the Waikato River about 9.7km downstream from the Tuakau bridge.
She was wrapped inside a bedspread from her own home and copper wire was found around her legs, where police believed a weight had been attached.
She had been killed with a single .22 calibre bullet to the head.
On September 16 Harvey's body was found, snagged among weeds in the same river about 5km downstream from the same bridge.
He had also been killed by a single bullet to the head.
Harvey's body had been weighed down with an axle - an item of evidence that would prove to be highly contentious over the coming years.
After analysing all of the information from the crime scene, witnesses and post-mortem examinations, police established the couple had been shot dead in their living room between 7pm and 9.30pm on June 17.
They had last been seen alive at 2.30pm, at a stock clearance sale in Bombay.
It's thought they headed back to Pukekawa late afternoon and their car was seen parked on the side of the road 2km south of their home at about 5.10pm, presumably as Harvey shifted sheep or tended to stock in a nearby paddock.
The night of the murder Jeanette fed Rochelle and put her to bed, then served dinner - flounder, potatoes and peas.
After eating Harvey then moved to his armchair and Jeanette to a sofa on his left.
She was knitting - a jersey for her husband - when the killer confronted them.
Police believe Harvey was shot first from behind, by someone standing in the kitchen or just outside the open louvre window.
The shot to the left side of his head, just above his ear, would have killed him instantly.
The killer then advanced into the lounge.
"It is likely that Jeanette verbally challenged the offender in some way, possibly by screaming or shouting," police would later say.
Jeanette was struck in the face and then at some point her head hit the front left corner of the hearth, which would have incapacitated her and left her lying prone on the carpet.
There, she was shot at close range in the right side of the head.
The killer - or killers - then set about dragging the bodies out of front door, leaving Rochelle in her bedroom just metres from the exit.
The gory scene went unnoticed for five days despite a number of people coming and going from the Crewe property, including the delivery man and stock agents.
As the search for the missing couple continued police spoke to neighbours, family, the community and people who thought they had seen the Crewes.
Neighbour Julie Priest - the wife of Owen who went to the house initially with Demler - told the cops she'd heard three gunshots on the 17th, probably after 8.30pm.
Bruce Roddick told police he saw a woman outside the Crewe house in the days between the murder and Demler finding Rochelle.
The theory fast became that she was an accomplice to the killer and snuck back to the house to care for baby Rochelle.
Medical opinion was divided on whether the toddler was fed during those days, with some saying she could have survived without food or water and others saying she certainly must have been tended to.
This sighting has never been independently confirmed, nor has the woman ever been identified.
One of the earliest suspects was Demler, who first had it put to him the day Harvey's body was found that he had killed the couple.
During a three-and-half hour interview he strongly denied any involvement in the deaths - something he maintained until the day he died.
The same day police started collecting .22 calibre rifles from people who lived in a 8km radius of the Crewe farm.
Within 10 days they had almost 50 firearms, including one belonging to Arthur Allan Thomas, who also farmed in Pukekawa and knew the Crewes.
On September 7, Thomas was taken to the police station and told that his rifle "was that which fired the bullets that killed Harvey and Jeanette".
He denied having anything to do with the murder.
The axle used to weigh Harvey down was then identified as being a 1928 Nash Standard Six 420 series front axle that had formerly been fitted to a trailer made in 1959 and eventually on-sold to Thomas' father, Allan.
Police ascertained that in 1965 the axle was removed from the trailer in the course of upgrading it for Thomas himself.
The Nash axle was returned to Thomas' brother Richard, who took it back to the family farm on Mercer Rd, Pukekawa.
Thomas was spoken to repeatedly by police about the axle and his association with the Crewes.
After a bullet fired from his rifle was found in a flowerbed outside the killing scene, Thomas was arrested and charged with murdering the Crewes.
A jury found Thomas guilty in 1971 - and again after a retrial in 1973.
But that was far from the end of the story.
After spending nine years behind bars as a convicted double-murderer, Thomas was granted a pardon on the basis that the police case against him was not proved beyond reasonable doubt.
A subsequent Royal Commission of Inquiry found that the cartridge case found in the flower bed at the Crewe house had been planted by Detective Inspector Bruce Hutton and Detective Len Johnston. The officers were never charged.
And no one else has ever been arrested for the murders - though many fingers have been pointed.
In 2010 Rochelle Crewe, then in her 40s, contacted police and raised concerns about the initial investigation, asking what if any further investigative action had been taken after Thomas was pardoned to identify the person who gunned down her parents.
She also demanded answers around why evidence-planting cops Hutton and Johnston had not been prosecuted.
Then-Commissioner Howard Broad appointed a team of experienced senior investigators and analysts, led by Detective Superintendent Andy Lovelock, to undertake a review of the investigation.
Part of that investigation was revealed by the Herald in August 2013 after Thomas, two of his brothers, his sister Margaret and her husband Buster Stuckey were all interviewed by police - with some asked to provide alibis.
A rifle belonging to Thomas' brother - not the same one taken in 1970 - was taken away by police for testing.
Thomas told his family that during his interview police grilled him about Stuckey - what access he had to the family farm at the time of the deaths.
Police then interviewed Stuckey and asked him for an alibi.
"He asked me where I was on the night of the murder ... He rang back the next day and asked again," Stuckey told the Herald at the time.
His wife added: "I know exactly where Buster was the night of the murder. I know exactly where we both were. But I don't feel compelled to answer that question.
"Arthur had an alibi. We knew where he was on the night of the murder and look where that got him. It didn't make any difference."
In 2014, after almost four years of work, the review team released their final report to the public.
They said no new evidence had come to light to implicate any specific person as being responsible for the double murder, or provided a basis for initiating further inquiries.
Though the review team could not pin the blame on anyone, they said the killer was someone who had access to items from the Thomas farm and they were firm on the fact that Thomas' firearm was most likely to have fired the fatal bullets.
But a re-investigation was "not warranted".
Police also acknowledged shortcomings in the murder investigation and, for the first time, admitted that officers fabricated evidence against Thomas.
Though they felt the 1970 police investigation team did a lot of things correctly, it was also conceded there were numerous balls dropped, including failing to corroborate some alibis, follow up on vehicle sightings, secure crime scene exhibits and evidence and investigate people of interest connected to the Thomas farm.
The team also finally - and to Rochelle's relief - cleared Demler.
"The report shows some aspects of the original investigation were done well but there were shortfalls that led to missed investigative opportunities which have left her with enduring uncertainty over the death of her parents ... " then-Acting Deputy Commissioner Grant Nicholls said in an apology to Rochelle.
"I've also apologised over the report's finding that police could have reviewed the investigation into her parents' murder sooner."
The review into the case cost a whopping $400,000 to date and amassed more than 92,000 pages of work.
At the time, Rochelle said while she was disappointed in the missed investigative opportunities, she was grateful police had finally acknowledged the shortfalls and had apologised.
"We as a family deserved that. The names of my grandfather and grandmother were always being dragged through the mud," she told the Herald in her only interview to date.
"And while we've always known they weren't involved, I hope that this chapter has closed once and for all now the police have publicly made that finding."
Fifty years on, speaking about the case does little for Rochelle but darken the cloud she has lived under her entire life. It helps no one, she feels.
Lovelock, who has now retired from police, did not want to speak further on the case.
The officer effectively "in charge" of the Crewe case these days is Detective Superintendent Dave Lynch.
He said all the investigative work that could be done to date - had been done.
"Whilst the file is not "closed", there is no active work being done on the file at the current point in time," he told the Weekend Herald.
"On release of the review report in July 2014, police said that we were open to any significant and credible new information and this position remains unchanged.
"To date no such information has been brought to the attention of police."
The Thomas family wholly disagree that there is nothing more for police to do.
They were furious about the review, saying it cast a shadow over the entire family as potential suspects and was a "whitewash".
Thomas' youngest brother Des is still pushing for police to reinvestigate and says he will never give up the fight to clear his family name.
He has spent much of his own life analysing the case and he strongly feels police could - and should - do more.
He believes advances in forensic technology could enable police to re-examine evidence - blood and fingerprints found at the scene, for example - and is adamant that will identify the real killer.
"The disgusting part of this is that the police are not interested in reinvestigating," he said.
"It's frustrating … the battle we've had and are still having. All we're doing is what the police should be doing."
Des Thomas said it would mean "a lot" for his family to get definitive answers and remove the finger of blame.
The children and grandchildren of the Thomases were also living with the stigma associated with the Crewe case.
"It's been terrible, disgusting … you don't expect this in New Zealand, do you?
"It's devastating … seeing my children growing up knowing about this."
Read the full 328-page report on the Crewe murders at tinyurl.com/crewereport