The Northern Territory government's tough-on-crime approach is "negatively impacting mainly Indigenous families and communities," while failing to improve community safety, according to more than 20 advocacy groups.

In an open letter released ahead of a trial that will allow civilians to purchase and carry capsicum spray from September 1, the coalition of organisations argued the Country Liberal Party (CLP) government's policies are "doing more harm than good".

"We believe the NT Government must implement evidence-based initiatives, and we strongly believe that Indigenous-led community safety models must be part of the solution," the letter, titled Civil Society Open Letter to the Finocchiaro Government, read.

While acknowledging crime and safety are serious issues, the signatories — including Catholic groups, the Aboriginal Medical Services Alliance NT (AMSANT), Victims of Crime NT, Justice Reform Initiative (NT), and Justice Not Jails (JNJ) — criticised the government for "rolling out these initiatives in the name of victims of crime" at the behest of an evidence-based approach.

"Ill-thought-out reactions can result in victims of crime not being protected at all. There is no evidence that spreading weapons through our community deters or reduces crime in the long term," the letter read.

"We are alarmed about the potential consequences of NT Government policies. Arming the public with pepper spray risks escalating violent incidents. Allowing guns on public transport and in public housing exposes the poor and marginalised to an increased risk of violence, arrest and even the possibility of deaths in custody."

Despite widespread criticism from experts and community leaders who argue the measure will worsen harm without improving safety, the government has pressed ahead with its OC spray trial.

"Weaponising the public as a safety measure defies logic. This policy will only lead to more violence, more people being criminalised, and more pressure on a justice system already stretched beyond breaking point," AMSANT CEO Dr John Patterson said.

"It is especially dangerous for vulnerable people, including those sleeping rough, many of whom are Aboriginal. Real safety will only come from investing in housing, healthcare and community-led supports that address the root causes of harm."

The government has also announced plans to arm public safety officers — condemned as a "deeply irresponsible escalation" — alongside other punitive measures such as lowering the age of criminal responsibility to 10, reintroducing spit hoods in youth detention, and expanding mandatory sentencing.

Her Story Mparntwe Co-founder and Managing Director, Chay Brown, urged the government to be "smart on crime" instead of tough.

"Introducing more weapons into the Northern Territory flies in the face of the evidence. We know that access to weapons increases the risk and severity of violence, particularly domestic, family, and sexual violence," she said.

"If we want our communities to be safer and healthier, then we must pay attention to the evidence and address the root causes — that requires collaboration and community-driven solutions. We've had enough of baseless and divisive rhetoric — let's be smarter and let's work together."

The CLP has defended its stance, saying Closing the Gap targets cannot come at the expense of community safety. Since taking office, the NT has recorded a sharp rise in incarceration, with more than one per cent of the population behind bars. The Territory now has the second-highest imprisonment rate in the world, behind only El Salvador.

JNJ spokesperson Thomas Mayo said the government must change course.

"We have seen law after detrimental law introduced, laws that criminalise our youth, introduce weapons into our community, and further marginalise and incarcerate Aboriginal communities," he said.

"Record-high incarceration rates and more weapons in our community will not make anyone safer. Justice not Jails is urging the CLP to listen to the evidence and to the signatories of this letter."

The letter concludes by noting tackling "poverty, trauma and discrimination, as well as helping people regain a sense of identity", are proven ways to reduce crime and improve community safety.

"There must be consequences for wrongdoing, but increasing the incarceration rate is a simplistic response to a complicated reality," it read.

"We need to help people rebuild their lives with the support of their families and communities. If we do this, crime is much less likely to occur."