New Zealand police are to carry a double-shot Taser stun gun that fires two high-powered charges without officers having to reload.

Superintendent John Rivers confirmed yesterday the force was planning to replace its fleet of Taser X26s with a more current model, the Taser X2, which allows for a "back-up shot".

"The routine and pre-programmed replacement of the New Zealand Police Taser fleet means police have the opportunity to replace the fleet with the most up-to-date model," he said.

The new model is similar to the version currently in use, firing two small prongs that attach to a suspect's clothing or body, but comes with more built-in "self-diagnostic computing tools" and can fire two cartridges without manual reloading, which can be challenging in high-risk standoffs, Mr Rivers added.


The development comes after several incidents in which the older model failed to work on armed suspects.

In July 2010, police in Auckland shot a 38-year-old man after a Taser proved ineffective.

A week earlier the stun gun failed during an incident in Christchurch in which two officers were shot and a police dog was killed.

Less than a fortnight ago, a 27-year-old Somali man was tasered then shot by police after an alleged kidnapping and stabbing rampage, also in Christchurch.

The man was pepper-sprayed then tasered, but witnesses said the shock did not work and made him angrier.

Green Party police spokesman David Clendon said this could be a creep towards Tasers being used more often, something the party was worried about before they were trialled in 2007.

"I would like to see the justification by the police, why they would need such a weapon," Mr Clendon said.

"We know that the weapons can be lethal - there have been recent examples internationally of people being killed by being tasered. I'm sure nobody wants that, including the police."

He was worried the more powerful models could normalise high-level responses over lower-level responses.

"We don't want these things to become the default response, rather than a high-end response to extreme situations.

"They are capable of killing people, and not necessarily old people, or frail people. We have had examples of quite young, fit people being killed by these things internationally."

Mr Rivers said the national Taser programme had been a resounding success in stopping violence offences.

"The mere presentation of a Taser is sufficient to stop violent and threatening behaviour 80 per cent of the time," he said.

This makes the Taser a valuable tactical option."