Dwyer, 19, and friend Bernadette Burns, 21, were arrested in Queensland on Friday over the death of the Mr Whitwell. Neighbours found his body on August 8.
The pair, from Redbank Plains, about 30km southwest of Brisbane, are expected to be extradited to Adelaide on Monday afternoon and charged with murder.
The alarming development on Saturday brought Mr Whitwell’s younger brother, who lives in Wallaroo, to tears.
“You couldn’t ask for a better brother,” he told the Sunday Mail. Mr Whitwell’s grandson posted a Facebook link to an advertiser.com.au story on August 16 about his grandfather’s then unexplained death, saying: “For someone who didn’t like the internet, Poppa, you’ve really gone viral! Let’s hope the truth comes out.”
Neighbours Paula and John Elworthy told the Sunday Mail Dwyer gave them the keys to her grandfather’s letterbox and asked them to collect his mail.
“She even said it was a shock to everyone what’s happened,” Mrs Elworthy said. “We didn’t even know Bob had a granddaughter (but) we knew he had a grandson.
“It’s just hard to get your head around.”
Mrs Elworthy described Mr Whitwell as a perfect neighbour and “lovely man and a real gentleman” who kept his home and garden meticulous.
She said he would take out their bins, while she and her husband would help him with his shopping.
“He was a very independent man who would keep his garden looking lovely,” she said.
“He had a great sense of humour, he always had a story to tell, a yarn.”
Mrs Elworthy said Mr Whitwell was very security conscious and had increased the height of his front fence after finding a strange man in his back yard about two months before his death.
He was also concerned about a strange car in the area but police said neither of those matters were connected to his death.
Mrs Elworthy also said it was “odd” Mr Whitwell’s Edward Ave home had been unlocked when his body was found.
“There are a few things which just don’t add up,” she said.
Mr Elworthy said he and his wife had never seen Dwyer, or Burns, before.
“We’re just in shock,” he said.
Mr Elworthy, and another neighbour who asked to be known only as Brian, found the body of Mr Whitwell in his home at 11.30am on August 8.
They had become concerned when an unread newspaper remained in his driveway and contacted police who, at the time, said there were several factors about his death that could not be fully explained.
Brian said he saw Dwyer outside Mr Whitwell’s house about four days after he was found dead. He said Dwyer did not seem distressed.
“She was on her phone, sitting in the gutter outside the home,” he said.
“I’m still scratching my head wondering what happened in there and why.”
Other neighbours said Mr Whitwell made daily visits to his wife, who suffers from dementia and lives in a nearby nursing home.
Detective Inspector Greg Hutchins, of the Major Crime Investigation Branch, described Mr Whitwell’s death as “shocking” but not brutal.
He said Mr Whitwell’s family were “devastated” upon learning of the arrests.
“It was one of those scenes that was very difficult to read so we needed all the expertise to examine (the circumstances of Mr Whitwell’s death),” Det-Insp Hutchins said.
He said police had planned to hold a meeting last Thursday but a tip-off led them to send six police officers, including Major Crime detectives, to Brisbane instead.
Those officers conducted numerous interviews and property searches on Friday.
Dwyer and Burns appeared briefly in Brisbane Magistrates Court yesterday morning but SA Police were unable to extradite the pair because they did not have a warrant.
They will reappear in court tomorrow when SA Police will again seek their extradition to Adelaide, where they will be formally charged with murder.
It is expected that they will face court in Adelaide on Tuesday.
Det-Insp Hutchins said he was unable to disclose any motive or cause of death.
He also declined to say whether Dwyer or other family members had been interviewed by police while they were in Adelaide.
“Police are not able to elaborate further on … what factors in the case were initially considered ‘unexplained’,” Det-Insp Hutchins said.
These factors are central to the ongoing investigation.”
Anyone with information about this incident should contact Crime Stoppers on 1800 333 000.