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The sister of one of the women killed in one of Victoria's most infamous cold cases has said she always knew an arrest would one day be made.
A man was arrested in Italy as part of the investigation into the 1977 murders of Suzanne Armstrong and Susan Bartlett at their home on Easey Street, Melbourne.
The 65-year-old dual citizen of Australia and Greece was arrested at an airport in Rome on Thursday night, nearly 50 years after the incident – making it Victoria's longest-running cold case to be solved.
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Armstrong and Bartlett were found dead in their homes on Easey Street in Collingwood on January 13, 1977.
Both of them, aged 27 and 28, had been stabbed several times.
Suzanne's sister Gayle Armstrong has spent every day waiting for news of the arrest.
"I just thought one day. One day," she told 9News.
Asked about the efforts of police in making an arrest, she said "it was unbelievable".
"(Police) were so persistently consistent, I knew that it would happen one day."
Around the same time, police found and checked a then-teenager near Easey Street, and recorded that he was carrying a knife.
In a reinvestigation into the crime, he agreed to provide DNA, but then fled to Greece.
Local laws in the country meant he had to be charged within seven years of the offence, and Australian police were unable to extradite him after diplomatic attempts failed.
He was instead placed on an international watch list, leading to his arrest in Rome 16 years later.
He remains in custody and is expected to be extradited to Victoria but police say it could be months before that happens.
Australian homicide detectives will need to gather their evidence before presenting it to an Italian court.
The Italian court will then decide whether there is a case to be made against the man.
Armstrong and Bartlett had last been seen alive on January 10, 1977.
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Armstrong's 16-month-old baby was found alive and unharmed in his cot when police found the women's bodies.
"For two quiet families from country Victoria it has always been impossible to comprehend the needless and violent manner in which Suzanne and Susan died," a statement from the families read.
"The gravity of the circumstances surrounding their deaths changed our lives irrevocably. We will be forever grateful for the support and understanding shown to us.
"It is difficult to sufficiently express our appreciation to Victoria Police and the many investigators who have tirelessly pursued answers and justice for us over such a long period of time. The perseverance and dedication required to achieve the result today is something to truly behold. For always giving us hope and never giving up, we simply say, thank you."
Victoria Police Chief Commissioner Shane Patton said homicide detectives have worked tirelessly for four decades to solve the case.
"The Easey Street murders, as they came to be known, have always been a priority for Victoria Police," Patton said.
"This was a crime that struck at the heart of our community – two women in their own home, where they should have felt their safest.
"While we still have some way to go, this arrest is an important breakthrough.
"I also want to recognise the enduring resilience of both the Armstrong and Bartlett families, who have grieved for over four decades and no doubt this will be a very emotional time for them.
"I hope this arrest brings you closer to the answers you so richly deserve and have waited so long for."
