The Darwin Children's Court has found the tasering of a 12-year-old boy who was running away from police was "improper".

The boy, who cannot be identified, was facing court over offences relating to the theft of a car by three boys who took it for a joyride around Palmerston in November last year.

The 12-year-old was a passenger in the stolen car when it pulled into a Bakewell petrol station.

The court heard when police confronted the trio at the petrol station, the unarmed 12-year-old was tasered by Sergeant Benjamin Watson from a distance of three metres when the boy tried to run away.

The child pleaded guilty to unlawful use of a vehicle, but not guilty to resisting arrest, escaping custody and driving a motor vehicle while unlicensed.

The boy's defence lawyers argued the use of the taser was unlawful, therefore the court should find the child not guilty of the charges that related to his apprehension.

Judge Tanya Fong Lim agreed with the defence and said the "impropriety outweighs [the boy's] offences".

Tasers not to be used on children or around volatile liquids

The court heard tasers were not allowed to be used against a young child, as well as near volatile liquids or near a car that might lose control, unless there were exceptional circumstances.

Judge Fong Lim said there were no extraordinary circumstances that warranted the use of the taser on the boy, especially so close to a petrol bowser.

"At the time [officer] Watson raised his taser he was aware of these things," Judge Fong Lim said.

"I could be satisfied that the arrest was unlawful."

Judge Fong Lim said there was "no immediate danger to Watson" and "the taser should not have been deployed".

She also ruled the offending of the boy "was not of a particularly serious nature" and the "impropriety of raising the taser [by officer Watson] is grave".

The boy, whom the court heard had never been in trouble with police before, received a six-month good behaviour bond.

Judge Fong Lim said she took the boy's suffering into account when making her decision.

"[Being tasered] must have been very painful ... unfortunately for you, you suffered at the hand of that," she said.

"There's a reason they are not to be used on children."