Detective Sergeant Tania McKenzie, who has worked in Kununurra since 2015, gave evidence to a coronial investigation into a cluster of suicides by 13 young Indigenous people in the Kimberley.
The officer told the inquest that kids in the region are having sex at a very young age, which becomes a "massive issue" when they become addicted to illicit substances.
"It is accepted in a lot of places you will get paid for sex," she told WA Coroner Ros Fogliani.
"People are learning from others that a good way to get your drugs or a good way to get your alcohol is providing sex or sexual favours."
Det Sgt McKenzie said the practice has become normalised, as has sexual assault in some areas, and she called for better education to stamp it out.
She says the region has extreme rates of domestic violence but it's difficult to get Indigenous women to testify against their perpetrators in court amid family pressure to drop the charges.
Det Sgt McKenzie says community support is largely behind the offender, not the victim, and even immediate relatives often turn a blind eye and refuse to give statements to police.
"Time and time again I hear families say 'she put him in jail'... not 'he put himself in jail by offending'," she said.
Det Sgt McKenzie wants mandatory reporting of family violence, initial police video interviews to be admissible as evidence in court and more restraining orders so offenders can't "stand over their victims and get away with it."
The court had previously heard 80 per cent of crime in Kununurra is booze-related, and the detective said it's disgraceful that a town with such "epidemic" alcohol issues has no rehabilitation centre.
On Thursday the court also heard a 21-year-old man who took his own life in 2015 after a drinking bender hadn't received counselling despite making previous self-harm threats while drunk.
Senior Sergeant Steve Principe, who's been Officer in Charge of Kununurra since 2015, told the inquest current liquor laws restrict daily bottle shop purchases to two cartons of full strength beer or six bottles of wine, which he calls excessive.
"We'd like to see it halved," he said.
Sen Sgt Principe also wants to see higher penalties for "sly groggers" who bootleg booze at inflated prices to vulnerable communities.
He says the federal government's cashless welfare card has contributed to a reduction in alcohol-related offences, and Kununurra has gone 12 months without a suicide.
"As a community, we're starting to turn a corner," Sen Sgt Principe said.
"But we've only just scratched the surface."
Readers seeking support and information about suicide prevention can contact
Lifeline on 13 11 14. Local Aboriginal Medical Service details available from www.bettertoknow.org.au/AMS
- With AAP