Posted by 
The grandmother of a 16-year-old boy charged over a crash that killed a woman has spoken out.
She claimed the woman's death could've been prevented, describing out-of-control teens as "animals" and insisting he should have been behind bars.
In posts to social media, the boy was seen flooring it in an allegedly stolen car, showing off a large machete and taunting other children.
READ MORE: Man, 32, charged with murder after 15-year-old found dead in Sydney bushland
His followers knew all about it and 9News has uncovered the videos documenting the abhorrent behaviour of a 16-year-old boy who now finds himself behind bars.
He was allegedly behind the wheel of a stolen Audi that slammed into 69 year-old grandmother Rosemary Franzidis last Thursday at Murrumba Downs in the Moreton Bay region near Brisbane.
READ MORE: Woman dead, man under police guard in hospital after incident at Sydney hotel
The teen, who can't be named for legal reasons, was charged with her manslaughter.
The teen's grandmother has called for out-of-control teens to be held responsible.
"Hold these animals accountable for what they're doing. They're not kids, they're animals," she said.
She showed no sympathy for the situation the teen had found himself in, saying he came from a loving home and was given every opportunity to live a good life.
"But the moment he knew when that police officer said to him at 14, you don't have to go home with your grandmother, that started a trail," she said.
It's a path of destruction his family and even the courts couldn't steer him away from.
"When you go up to court 16 times and breach your bail, who let him out? Who said that this child was ok to be on the streets?" she said.
The teenager's family is adamant this could've been prevented, arguing he was dangerous and a risk to others as long as he was out in the community.
"The legal system and these judges, that are letting these animals out, they need to be held accountable," the grandmother said.
"We can't have any more victims. It has to stop, and I'm going to scream and stand up and make sure that no one else is hurt."
The grandmother's thoughts are solely with the heartbroken family of beloved Rosemary.
"Know from my soul, that I am so so so so deeply, sincerely, and heartfelt sorry," she said.
Queensland premier David Crisafulli has pledged to take action on youth crime.
"I want Queenslanders to know our priority is to stop that revolving door that just goes round and round it must change and it will," he said.
