On Sunday night, Australian True Crime Stories will look into the baffling and brutal Australian serial rapist and killer known as Mr Cruel. Here’s what we know about Mr Cruel’s Melbourne terror reign and his helpless victims.

Thirteen-year-old Karmein Chan was babysitting her two younger sisters at their family home in the Melbourne suburb of Templestowe in 1991, when she became the victim of Australia’s most prolific serial rapist Mr Cruel.

And soon-to-be murderer.

It was the school holidays. While their parents were working at the family’s Chinese restaurant 10 minutes from their suburban home, Karmein and her sisters were watching a Marilyn Monroe documentary when they got up to get something from the kitchen at around 9pm.

There, they found a masked man wielding a large knife, his face completely covered by a black balaclava with white stitching around the eyes and mouth. After forcing Karmein’s sisters into a cupboard and barricading them in by pushing a bed up against the door, the man later known as Mr Cruel dragged the teenager through the house, past the family’s Toyota Camry, through the garden gate and out onto the street.

Vice reports Karmein's scent led police to a vacant block 300 metres away. There, the trail went cold, and Karmein wasn't seen or heard from again. A year later, her remains were found in bushland - she'd been shot three times in the head.

Karmein was the fourth of Mr Cruel's official victims - Victorian police linked the perpetrator to three other unsolved violent abductions and sexual assaults. Sadly, Karmein was the only victim, that we know of, who never made it home.