Laser Tag

The Department of Justice is working on two "portable non-lethal" weapons descended from the Air Force's "pain beam" Active Denial System—and wants to put them in the hands of your local boys in blue.

Like the ADS, the new portable devices will also heat the skin, but will have beams only a few centimetres across. They are designed to elicit what the Pentagon calls a "repel response" - a strong urge to escape from the beam. A spokesperson for the National Institute for Justice likens the effect of the new devices to that of "blunt trauma" weapons such as rubber bullets, "But unlike blunt trauma devices, the injury should not be present. This research is looking to reduce the injuries to suspects," they say.

Existing blunt trauma weapons can break ribs or even kill, making alternatives welcome. Yet ADS has recorded problems too - out of several thousand tests on human subjects there were two cases of second-degree burns. The NIJ's laser weapon has been dubbed Personnel Halting and Stimulation Response - PHaSR - and resembles a bulky rifle. It was created in 2005 by a US air force agency to temporarily dazzle enemies, but the addition of a second, infrared laser makes it able to heat skin too. The NIJ is testing the PHaSR in various scenarios, which may include prison situations as well as law enforcement.

The NIJ's portable microwave-based weapon is less developed. Currently a tabletop prototype with a range of less than a metre, a backpack-sized prototype with a range of 15 metres will be ready next year. The truly portable mini-ADS could prove the more useful, as microwaves penetrate clothing better than the infra-red beam, which is most effective on exposed skin. Although the spokesman says: "In LEC use there is always a little bit of skin to target."