On June 17, 1970 Harvey and Jeanette Crewe were gunned down in the living room of their Pukekawa farmhouse.
Their bodies were dragged from the home and dumped in the nearby Waikato River.
Jeanette was wrapped in a bed cover from her own home.
Harvey was weighted down in the water with an axle.
Their baby daughter Rochelle, not even 2, was left in her cot in the rural farmhouse and was there for days until her grandfather chanced upon the grisly crime scene.
Fifty years have passed since the brutal crime - which remains unsolved despite one man being convicted twice of murder.
In episode seven of Herald podcast A Moment in Crime, we look back at the infamous cold case - one of New Zealand's most enduring murder mysteries.
On the night of June 17 1970 Harvey and Jeanette Crewe put their daughter to bed, sat down to eat dinner and then moved to the living room to have a cup of tea and relax before bed.
The Pukekawa farming couple had been to a stock sale earlier that day and were expecting stock agents to call at the house early the next morning.
But when the agents arrived, there would be no sign of the couple.
Jeanette's father Len Demler was called to their farmhouse the next afternoon after various people failed to get hold of the pair.
He walked into what would become New Zealand's most famous crime scene.
There was blood in the living room, baby Rochelle was in her cot - dirty, starving and neglected - and Demler could not find his daughter and son-in-law.
And, the axle used to weigh Harvey's body down in the river would later be connected directly to Thomas and his family farm.
Both men strenuously denied killing the couple and provided alibis.
But in November 1970, after police located a bullet shell in the Crewe's garden that matched his rifle. Thomas was charged with the double murder.
Thomas was found guilty of the murders in 1971 and again at a retrial in 1973.
But in 1979, after he had spent nine years in prison, he was granted a pardon on the basis that the police case against him was not proved beyond reasonable doubt.
In 1980, a royal commission of inquiry found that the police planted evidence that was used to wrongly convict Thomas and that the farmer should never have been charged with the murders.
The commission said neither Thomas nor his rifle was involved in the murders, which remain unsolved. He was later paid $950,000 compensation.
In 2010, the Crewes' only child, Rochelle, asked police to reopen their homicide investigation in a bid to find out who killed her parents.
Police agreed to review the case and spent four years poring over evidence.
They finally concluded that while there had been shortcomings in the initial investigation - all evidence pointed back to the Thomas farm.
Someone connected to that property, they say, killed the Crewes.
Police also acknowledged, for the first time, that officers planted evidence against Thomas.
To date, no one else has ever been charged with the murders.
The case remains open - but is not being actively worked on.
The Herald looked back at the Crewe murders for the 50th anniversary of the case. Episode seven of A Moment In Crime delves further into the murders - the timeline to the tragedy and the disastrous aftermath.
A Moment In Crime is written and hosted by Anna Leask, senior crime reporter for the Herald. The podcast is produced by Chris Tarpey. Frances Cook is the executive producer.
Leask has been covering crime and justice for the Herald for more than a decade and has reported on most of the major incidents and events over that time.
"Each month I'll take you inside some of our most infamous incidents, notorious offenders and behind the scenes of high profile trials and events to show you what's really happening in your backyard," she said.
"Heroes and villains battle for justice to be done, and it seems no matter how horrifying the story, we always want to know more.
"If you want to know more about the cases that have shocked and shaped our nation - from murders and massacres to violent villains and the utterly unbelievable - join me for A Moment In Crime."
In our first episode, we looked back at the Christchurch terror attack - what unfolded on March 15 and how it changed New Zealand.
The podcast has also delved into the death of West Auckland toddler Aisling Symes, the cold case murder of Kayo Matsuzawa and double killer Jason Somerville, infamous for the Christchurch House of Horrors.
In 2017, Leask wrote and hosted Chasing Ghosts - a six-part podcast series on the Amber-Lee Cruickshank case.
The South Island toddler disappeared almost 27 years ago from a small town on the shore of Lake Wakatipu.
Despite exhaustive and repeated searches, there has never been any sign of the little girl.
To mark the 25th anniversary of Amber-Lee's disappearance, Leask investigated the famous cold case in a bid to generate some answers for the toddler's family.