It's been 25 years since Martin Bryant brutally murdered 35 people – the deadliest mass shooting in Australia's history.
But damning new allegations, detailed by former neighbours of Bryant, have revealed the people tragically killed on April 28, 1996, might not have been his first victims.
In allegations aired on Channel 7's Spotlight, Bryant's former neighbours and associates spoke about his longstanding friendship with an older, wealthy woman named Helen Harvey.
Harvey died in October 1992, less than four years before the Port Arthur massacre.
Her death was always believed to be an accident after the car she was driving, with Bryant in the passenger seat, crashed on a remote country road in Tasmania.
However, friends of Harvey told the programme she had said she feared Bryant would one day kill her after his odd tendency to grab the steering wheel while she was driving created problems for her on the road.
Witnesses to the crash said they saw Harvey's car "swerving" before it ran off the road, killing her and leaving Bryant injured.
Barry Featherstone, one of Harvey's neighbours, said he had previously helped free her car from a ditch after Bryant pulled a similar stunt.
"I think very strongly he did it," Featherstone told Spotlight.
"She was telling us how he used to grab the steering wheel and put her off the road.
"Well her exact words [were] one of these days, that little bastard is going to kill me."
Featherstone told police about three separate incidents where Bryant had grabbed Harvey's steering wheel.
He said the elderly woman was notorious for driving slowly due to her fears Bryant would grab the wheel.
Harvey and Bryant became friends – despite their 35-year-age gap – after Bryant started doing odd jobs around her property.
The two were living together when she died in October 1992 and Harvey left all her money and property – valued at more than $500,000 – to Bryant.
In another startling twist, Bryant's father Maurice died less than a year after Harvey was killed in the car accident.
A neighbour of the Bryants called the police after discovering a note, written in Maurice's handwriting, pinned to the front door.
The note read "call the police".
Police called to the property to take part in the search for Maurice told Spotlight Martin asked out a policewoman who had been assisting in the investigation.
Hours later, Martin watched on as police divers pulled Maurice's body from a dam on the property.
Tied around his neck was his son Martin's diving belt, strung with heavy lead weights.
His death was ruled a suicide by the coroner.
Documents from the National Archives in Hobart, obtained by Spotlight, showed the final will and testament for both Harvey and Maurice Bryant.
Harvey's will left her house and farm to Martin – however Maurice was named as trustee, meaning Martin had no power or ownership over her property while his father was alive.
Maurice's will also left $269,000 to his son Martin which meant the younger Bryant stood to collect a farm, a house and $269,000 once Harvey and Maurice had died.
Spotlight suggests the amount Martin had to gain from both Harvey and his father's deaths were motive enough to commit the murders.
Maurice's suicide has long been linked to David and Nolene Martin refusing to sell him their Seascape Hotel.
The Martins were the first two people Bryant killed on April 28, 1996.
Bryant 'virtually unrecognisable'
Bryant, now aged 54, will spend the rest of his life in Tasmania's notorious Risdon Prison after he was given 35 life sentences in 1996.
Tony Burley, a former Risdon prison guard, said Bryant had an uneventful life in prison because he never has, and never will be, let out into general population.
"He wakes up, he goes to sleep basically," Burley said.
Recent photos of Bryant showed the mass murderer had gained a lot of weight in prison.
Burley said the killer had put on weight because he was being "rewarded" for giving sexual favours in the prison canteen.
"His long blonde hair was gone and he began to put on weight – [he's] virtually unrecognisable," he said.
"He has ... increased his calorie intake due to sexual favours from the prison canteen."