A Ballarat man has been arrested over the stabbing murder of an Adelaide woman more than a quarter of a century ago after DNA evidence linked him to the crime.
Mother-of-two Suzanne Poll was stabbed to death while she was working at the Sands & McDougall shop in John Street at Salisbury in 1993 and the case remained unsolved.
Police arrested a 46-year-old man from Ballarat on Friday after a warrant was issued.
He was unknown to police in South Australia or Ballarat, and was not previously involved in the investigation, but had lived 300 metres from the scene at the time.
The attacker had left "a considerable amount" of his own DNA at the scene after cutting himself.
Detective Superintendent Des Bray, the officer in charge of Major Crime in South Australia, said at a press conference on Friday afternoon more than 270 people had their DNA taken in relation to the case, but a familial match was found only recently.
Detectives and forensic investigators found a new match on a DNA database, then built a family tree to work through identifying suspects related to the match.
"On September 6, we obtained a DNA sample related to that offender, which we submitted for examination," Detective Superintendent Bray said the man was spoken to by police in Ballarat while waiting for results.
"He'd never come to notice in this investigation, so it's really starting this whole investigation again with him as the suspect.
Watch the police press conference here.
"Over the years we have checked the national database constantly, we have checked internationally a number of times to try and identify this DNA, and again without success."
Victorian cold case detectives arrested the suspect late Friday afternoon.
Detective Superintendent Bray said the man was in custody in Ballarat and police would refuse bail until he appeared before a magistrate.
Detectives will then apply for the man's extradition to South Australia.
"This, today is a very important breakthrough for the family, it's a very important breakthrough for the investigators, but it's very much the start of what will be a completely fresh investigation," he said.
Ms Poll was counting the takings at the shop when a man entered at closing time about 9pm on April 29, 1993.
"For reasons that are completely unknown to us, it's escalated into a vicious and sustained attack that has resulted in her death," Detective Superintendent Bray said.
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