7News Exclusive: How detectives caught Jason Downie

The head of South Australia's Major Crime Branch has recalled the confronting scene of one of South Australia's most notorious murders, the triple slaying of the Rowe family at Kapunda on November 8, 2010.

In an exclusive interview, Major Crime Detective Superintendent, Grant Moyle, has recounted to 7News Crime Reporter, Michelle Vella the experience that none of them could have been prepared for.

"You know as soon as someone says it’s three bodies it’s going to be a significant event," Det Supt Moyle said.

"We knew it was going to be significant as to what the circumstances were... From the outset it was going to be a hard job."

Andrew Rowe, his wife Rose and their daughter Chantelle had been killed inside their Harriet St home in the South Australian country town of Kapunda.

It was a frenzied, bloody stabbing attack that went through every room of the house.

It later emerged in court that Andrew was the first victim, stabbed 29 times when he caught Downie in their home.

Rose was then stabbed 50 times, after Downie realised she'd witnessed his attack on Andrew.

And Chantelle, his target, was stabbed 33 times.

"Unlike a lot of other scenes we attend, where you might only have one deceased in the house, here we had three members of one family dead in very violent circumstances,"

"It was a complex crime scene that included the entire inside of the house."

Det Supt Moyle had only recently taken over as head of South Australia Police Major Crime Unit and says the crime scene that he found was confronting - but he had a job to do.

"I had a look at the scene from the exterior of the house, from the windows to get some appreciation of what we were faced with and that was to preserve that crime scene because you only get one chance to recover evidence."

"Once you disturb it or contaminate it, destroy it, then it’s gone."

The daunting task lay ahead, and the hunt was on for the triple murderer who took three lives from the one family.

Andrew and Rose's son, Christopher, was in Queensland on holiday at the time.

"It’s confronting, you wouldn’t be human if you didn’t find that crime scene confronting," Det Supt Moyle says.

"And without trying to appear tough or otherwise, we have a job to and you have to get past that to do our job."

At the time, the tight-knit community was terrified, and sickened that the killer may have been amongst them.

"The enormity of this task wasn’t lost on us, the significance to the state wasn’t lost on us."

"So that’s a big statement to be making to the community and the issues of community fear, and how safe people felt, particularly in the Kapunda community was on our mind all the time."

"And, indeed, we didn’t have any suspects at that time."

The investigation swung into action, the whole process saw 86 officers door knock homes in Kapunda, interview friends, relatives and associates of the Rowe family.

220 statements were taken in total, and 150 tips to the CrimeStoppers line were followed up.

Within hours, detectives were certain Chantelle had been the target of the attacks.

Her friends were interviewed, and Jason Downie's name was mentioned.

"There was a lot going on," Det Supt Moyle said.

"But one of the tasks that was given to some of the uniformed officers was to go and speak to the known friends we had, as to when they last saw various members of the family and what their associations had been."

"That was the following day, the Tuesday."

"And it was on that day that one of the officer’s was taking a statement from one of Chantelle’s friends, he offered up the name of Downie at that stage."

"So then the officer went and took a statement from Downie on that second day and that’s when his name first came up and was linked as being an associate of Chantelle."

It wasn't until experienced Detective John Keane went over the statement and noticed Downie repeated several things.

Det Supt Moyle said Detective Keane noticed something wasn't right and it was decided they would ask Downie to volunteer a DNA sample and fingerprint.

"It didn’t quite fit right," he said.

"Experience tells you that perhaps we should have a closer look at him."

"They eventually went and spoke with him again to gain the DNA profile and the DNA swab and the fingerprint, and that was some days later."

"That was because we’d started the process of obtaining DNA and fingerprints of male friends of Chantelle as a result of forensic results that came through."

"He said he had been to Chantelle’s house but had never been inside."

"That was significant because of the fingerprint that we had inside the house."

Another clue struck detectives.

"At that time the detectives also noticed on the palm of his hand three cuts," Det Supt Moyle said.

"We didn’t ‘zero-in’ on him until a fingerprint identification came back that identified him, that match was only possible because of the voluntary print we obtained from him."

"Then the day after that when his DNA comparison came back from DNA we’d recovered from the scene."

But at the time, the match alone was not enough to arrest Downie for the murders.

"We were incredibly pleased when that fingerprint match came back, on its own it wasn’t enough, but it gave us some direction."

"We had a man, we suspected he’d brutally killed three people and as far as we could ascertain there had been no prior indications he had been a threat to the community or a danger to anyone."

"In a meeting in the office we discussed what our next steps should be, based on that and my concern of the threat that he posed to the community, we decided to arrest him that afternoon."

Eight days since the investigation began, Jason Downie was arrested after voluntarily attending the Kapunda Police station on November 16, 2010.

Later on in the investigation, a motive was identified - Downie's sexual obsession with Chantelle.

In court, his defence Lawyer maintained the crime was committed out of jealously, Downie wanted a relationship with Chantelle but couldn't have one.

On Tuesday, April 17, 2012, Jason Downie was sentenced to 35 years in jail, one of the longest terms ever imposed on someone in South Australia.

Outside of court, relatives of the Rowe family expressed their anger, saying the sentence was not enough.

"He should never be released," Sally Rowe told news crews, "When they say life, I reckon it should be life."

While Det Supt Grant Moyle agreed that no sentence would ever fully address the viciousness of the crime, he takes heart in the painstaking investigation that brought a cold blooded killer to justice.

"Starting off with no suspects, to arresting someone in eight days is a tremendous result I think."

"I’m very proud of all the detectives."

"I think the investigation followed very sound, tried and true investigation process. You can’t rush these things I know, we all know there was tremendous concern in the community."