She could not have been more vulnerable.

Just 13 years old with a hellish family life peppered with exposure to chronic alcoholism, domestic violence and substance misuse, alongside her own significant issues including malnutrition and possible foetal alcohol spectrum disorder.

In March last year, that vulnerability was callously exploited when the teenager was lured to a remote lookout above the Karratha townsite and sexually abused by five males.

While she was passed around like a plaything, the degradation was photographed and circulated so widely that the pictures were seen by pupils at a local high school. If that humiliation were not enough, the girl then tested positive for chlamydia and four other infections.

The case — one of the dozens emanating out of the widespread investigation into sex abuse in and around Roebourne — ended in convictions for six young men. More disturbingly, the District Courts in Perth and Karratha were told that such an environment, among those young people, “this conduct had been normalised”.

“She simply didn’t have any of the protective mechanisms you might expect a normal 13-year-old to have,” prosecutor Katrin Robinson said.

“To put it bluntly, saying yes to sex was not out of the ordinary for her because that’s what she was used to.”

An 18-year-old was sentenced to two years in jail by the Perth District Court in March. The 16-year-old ringleader was given 13 months detention by the Perth Children’s Court.

An 18-year-old, who was convicted of aiding a sexual penetration charge, got a 12-month suspended sentence.

One 15-year-old boy received 10 months’ immediate detention and another an eight-month intensive youth supervision order. A 17-year-old who took photographs of the sex acts got a nine-month suspended sentence.