IT SOUNDS like the screenplay for a tawdry horror flick - corpses shot with plastic bullets, people zapped with microwave beams and others knocked out with volatile narcotic gels. But this is not Hollywood fiction. This is the reality of non-lethal weapons research.

At first glance, developing weapons that incapacitate without killing seems a worthy goal. But a worrying number of devices may not be quite as non-lethal as potential victims might hope for.

Take the Taser stun gun, which incapacitates its victims with a 50,000-volt shock and is widely used in the US. The trouble with the Taser is that even after 10 years of use in the US, there are still serious concerns about its safety.

Human rights organisation Amnesty International cites numerous cases in the US in which a "tased" person later died. The maker, Taser International of Scottsdale, Arizona, is facing 33 lawsuits for wrongful injury, ...