THE family of a boy shot dead by police have vowed to fight for their "scared little boy," saying the officers involved had "pursued ... surrounded and hunted" down the teenager.

Tyler Cassidy, 15, was shot and killed when three officers opened fire on him in a Melbourne skate park last night after he allegedly threatened to kill them with two knives.

The shooting is being investigated amid revelations that Tyler was a member of a nationalist white supremacist group, and was prone to violent outbursts.

Both Victoria Police and the police union have defended the officers involved, saying they did everything they could to subdue the teenager.

"Died alone"

Tyler's mother, Shani, said in a written statement that she would "fight" for Tyler, describing him as a "scared little boy".

"He died alone without his family at his side, gasping his last breath," the statement said.

"The entire family and friends of Tyler Cassidy are appalled at the actions by Victoria Police last night.

"Their heavy handedness and lack of negotiating skills at the scene of the shooting contributed to the untimely death of our beautiful 15-year-old."

Warning shot

But Assistant Commissioner Tim Cartwright said the officers acted in accordance with their training and fired when they felt Tyler was threatening their lives at the Northcote park.

Mr Cartwright said a warning shot was fired before three of four officers involved in the standoff opened fire.

"He was saying 'Kill me, I am going to kill you'. He had been saying that through the confrontation," Mr Cartwright said.

"I don't think police were trigger happy but that's why we've got a coroner and the homicide squad to do a full investigation on (the coroner's) behalf.

"There was a young man with knives moving about, clearly intent on doing some damage or being damaged. There's certainly phone calls to suggest he was threatening members of the public.

Source: http://www.news.com.au/story/0,27574,24788737-1243,00.html