While officers have reportedly praised the quick-thinking action, according to The Age, Victoria's outdated laws where police would no longer need court approval to get DNA samples were supposed to go through parliament last year.
There are more than 55,000 crime scene DNA profiles held by police that do not match any person's profile.
It comes as the Victorian coroner is expected to release the international student's body today.
Her father, Saeed Maasarwe, had asked for his 21-year-old daughter's body to be released so he could lay her to rest.
He was among hundreds of mourners at a tribute held on Sunday.
The day before about 1000 people gathered outside a mosque in Israel calling for her return, chanting "we need Aiia home" and "we are all Aiia's sisters, Aiia is the daughter of all of us".
"The Land Wants Aiia Back," read some of the placards, while others called for an end to violence against women across the globe.
Her sisters also revealed chilling new details about her death including sounds of "screaming and screaming" as Aiia was apparently attacked.
Aiia's sister Ruba spoke further of the disturbing FaceTime phone call the two were having when Aiia dropped the phone and Ruba never heard from her again.
Hours later, about 7am Melbourne time last Wednesday, a passer-by found Aiia's half-naked body near the Polaris Shopping Centre in the northern Melbourne suburb of Bundoora.
Ruba Maasarwe recalled Aiia's final late-night safety call during an interview on Israeli TV station Channel 13.
"We spoke on the phone on FaceTime," Ruba said.
We spoke about the stand-up comedy she saw and when we would next meet.
"Suddenly I heard her scream.
"I heard vehicles in the background of the call like there was a phone on the floor.
"There was no sign during the conversation of the horror about to happen.
"I heard her screaming and screaming and then the call was cut off.'"