Lasers as Tactical Threats

Article excerpt

Patrol Sergeant Jim Freeman was tired. He had pulled two back-to-back uniformed shifts. The Chief had given him eight hours off to sleep, but he never rested very well during daylight hours. Now it was late in the evening and he was investigating suspicious activity at the old rail yard.

At sunset the wind had shifted, stirring up all those unseen things that aggravated his allergies. His sinus ached so badly he wanted to abandon his head on a park bench somewhere. Even with the pain and weariness that savaged his body, the upper level of his mind was on business.

Two days ago the department received a report that suspects from an armored car robbery might be in the area. Their haul included the guard's laser sighted handguns. Freeman reflected on his own holstered weapon, a department-issued semi-auto with nothing fancy on it.

Suddenly, even with his head wracked with sinus pain, he noticed a red brilliance reflected off of his badge. Spotting a dark silhouette 10 yards away, his reaction was instantaneous.

What Freeman did is a matter of record. How he should have responded is a matter of planning and training.

In simplest terms a laser is an intensely bright light. Unlike conventional light, laser light travels out from a device in a narrow beam, maintaining its brightness at long distances.

Most lasers found outside of research laboratories or medical/industrial facilities cannot penetrate metal or even damage skin, but the eye is vulnerable. As laser light passes into the eye, it is focused by cornea of the eye onto the retina located at the back of the eye. The retina, a layer of living cells, can be damaged or permanently destroyed by intense light. If cell damage occurs, the mechanism is essentially destruction by highly localized heat:

The actual effect on the eye will vary with the power of the laser, the time the laser is trained on the eye, and the portion of retina that the focused light impacts. The effect of looking into a laser beam can range from true blindness (unlikely in the scenario presented in this article) to dazzling (similar to close viewing of a camera flash) to annoyance. In many cases effects of the light will be short-lived, several seconds to some minutes. It is also possible that there may be temporary irritation or the presence of after images that may last several days but will disappear and cause no further problem.

This article addresses the dazzle effect, which has the greatest potential to cause problems in law enforcement. Reaction to dazzle has both physiological (physical) and psychological (mental) components. The relationship between these two aspects is not entirely understood. One response is the tendency for an individual to be startled by the sudden exposure to dazzling and overwhelming light. Sometimes an immediate, though temporary, loss of vision will occur. Functional vision loss can occur either because of the direct biological action of the light on the eye or indirectly by glare caused by reflections and scatter from other objects.

The Treat

Lasers were invented more than 30 years ago but in the last decade applications have multiplied and annual sales are in the billions of dollars. Lasers are smaller and more powerful, they cost less, and they're more available than ever before. Lasers are not only visible (colors range from red to violet) but also invisible infrared (below red) and ultraviolet (beyond violet).

Invisible beam laser weapons, most of Chinese manufacture, are openly advertised by world arms merchants. These are relatively non-portable and are most likely to be used by more organized criminals like terrorists or in narcotics operations. Military uses of these lasers include range finding, target designation, and live fire training (laser tag). Medical lasers, visible and invisible, are powerful and now as small as a suitcase, but they are expensive and require line voltage. …