Detectives have arrived in regional Victoria with plans to extradite a man over the decades-old cold case stabbing murder of a "completely innocent" Adelaide woman.
South Australian police travelled to Ballarat on Saturday after a DNA breakthrough led to a long-awaited arrest concerning the 1993 murder of Suzanne Poll.
A 46-year-old Ballarat man was arrested by Victoria Police on Friday afternoon and was remanded in custody.
He is due to appear at the Ballarat Magistrates Court on Monday for an extradition hearing.
Mrs Poll was stabbed to death while working at the Salisbury Sands & McDougall store during what police believe may have been a robbery-gone-wrong.The lights were off and the shop was shut, but the door front door remained ajar while the the 36-year-old counted the day's takings.
A man entered the store and attacked Mrs Poll, who tried to escape via a back room but was stabbed to death in a "vicious and sustained" attack.
But the killer was cut during the attack, leaving a "considerable amount" of DNA all over the premises.
Despite the man's blood being spilled at the scene, the killer had no criminal history and his DNA could not be matched to the national database.
South Australian police repeatedly submitted the DNA for testing in a bid to find a family member related to the the killer, and even tried to match the sample with international databases.
They had no luck until they tried again this month.
"We've checked that DNA constantly over the years and on each occasion it's been a negative result," Detective Superintendent Des Bray told reporters on Friday afternoon.
"Recently we again submitted the DNA for familial testing and we got a result that indicated the offender was likely to be related to someone who was on the database. From that we constructed a family tree."
On Thursday, investigators got written confirmation they'd struck a match, spending most of Friday trying to find the accused killer.
"(This) is a good example of the fact that we actually don't give up and we keep trying, no matter how many setbacks there may be," Det Sup Bray said.
