This is the story of the murder of Arthur Easton and the arrest of Alan Hall, a man with no alibi or answers.
But it's also a story about our system of justice - the power and trust we give to police and prosecutors… and their ability to find the truth.
Episode four explores the evidence surrounding the case, and tracing the steps that led police to suspect Alan Hall in the first place.
In the end, it was Alan Hall’s brother, Greg, who inadvertently led police to suspect him for the murder. Greg told police two pieces of crucial evidence - a brown hat and a military bayonet - belonged to his brother, making Alan a suspect.
Police spoke to Alan’s supervisor Paul Appleford at Sterling Pharmaceuticals where he worked. But Appleford said he saw nothing untoward in Alan’s demeanour the day after the murder took place.
If it is true that Alan Hall murdered Arthur Easton on October 13, 1985, Alan's defence team would later argue, surely there ought to have been some mark on him - some sign of such a vicious brutal fight.
But all the clues were pointing to Alan. When questioned by police, he admitted to owning the brown hat, and police also confirmed that the bayonet had been purchased for $45 by one Mr Alan Russell Hall.
Alan not only admitted to owning the items, but he lied about their whereabouts. He gave four inconsistent explanations saying he lost the items...then that he had thrown them out...then that a man had robbed him of them.
He claims he got scared being questioned by police.
That last version of Alan's story - that sometime in September 1985, a thief had entered his bedroom in the sleepout and stole the bayonet and hat - is the explanation that Alan and his family have stuck with ever since.
In the months ahead, the police would continue to slowly build their case against Alan Hall… but in reality, the foundation of that case was already set in stone.
Grove Road was created in partnership with Newshub Nation, which is made with help from NZ On Air.
Got a question or tip? Email it to firstname.lastname@example.org