Indigenous media personalities have joined the Yuendumu community in speaking out about the fatal shooting Saturday of Kumanjayi Walker, a 19-year-old Indigenous man.

A 28-year-old male Northern Territory police officer has been charged with one count of murder, police said in a statement on Wednesday.

The officer has been identified as Zachary Rolfe. Northern Territory Police Association President Paul McCue said Thursday of the officer: The member has made it clear that he will plead not guilty and will vigorously contest the charges. He, like all, has the presumption of innocence in his favour.

Indigenous communities have rallied in the streets and taken to social media to voice their concerns.

Actor Meyne Wyatt attended a Justice for Walker rally in Sydney on Wednesday evening.

You turned up today. We got a win. But the fight will go on. To the end, he wrote on Instagram after the protest at Sydneys Town Hall, which saw a turnout of hundreds.

Following the demonstration, Meyne told HuffPost Australia that the sentiment amongst the crowd was sombre.

I think the feeling is a down feeling, really, he said. Its a dreadful feeling we all had to gather around for the occasion, but we will do it and we will keep doing it to fight for whats right.

On Tuesday Meyne asked his Instagram followers to join the nationwide rallies that were being held, as he believed systemic change is needed and independent investigations need to be had.

People still want to live in this bubble of safety that things have improved. Well clearly, they damn well havent, wrote Meyne, whose father was from the Yamatji area and mother was from the Wongutha region.

What will it take for people to wake up?

I wont be silenced, he said. Tomorrow at 5:30 p.m. at the Sydney Town Hall, Ill be this loud black dog again. I want you there with me. This is a national call to action!