Laser threats to law enforcement.

Over the past year, police in Europe and the United States have received reports of juveniles temporarily blinding subway drivers with laser lights. Also, reports of British sports fans aiming laser pointers at soccer players and American basketball spectators shooting lasers at the eyes of opposing players on the free throw line have surfaced.

Law enforcement officers in the United States have begun experiencing similar situations. Low-power, visible-light lasers, whether designed for use in the classroom, laboratory, or on the battlefield, are the easiest to obtain, detect, and most likely to be used by low-tech hooligans. They also may be used as an alternative to firearms because of favorable laws that do not define possession of a laser as a deadly weapon.

Law enforcement officers could encounter low-power lasers during routine operations, such as traffic stops, or in special operations, such as hostage situations. In most instances, light from this type of laser would not, for the reasons of power and length of time on the eye, cause actual eye damage. However, the laser's incredible brilliance could surprise and functionally disable officers. Also, ungrounded fear of permanent blindness could further impair their judgment. The susceptibility of officers to this type of debilitation remains largely psychological and would depend on their preparedness, training, and the conditions at the time of the incident. What is this new threat, and what can officers do to protect themselves?

Lasers and the Human Response

In simplest terms, a laser is an intensely bright light.(1) Unlike conventional light, however, laser light travels out from the laser device in a narrow beam maintaining its brightness at long distances. Some high-power laser beams can vaporize steel or other materials. Also, laser beams are not only visible (colors that range from red to violet within the visible color spectrum) but also invisible at both the infrared and ultraviolet ends of the color spectrum.

Although invented over 30 years ago, in the past decade, medical researchers, military authorities, and even criminals have found multiple applications for laser devices. Like computers and digital cameras, lasers also have become smaller, more powerful, less costly, and more available than ever before. Annual sales now exceed $1 billion.

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 remain expensive and require line voltage as opposed to batteries. These uses represent some of the positive purposes of the technical advances in laser manufacturing. However, world arms merchants openly advertise invisible-beam laser weapons, notably of Chinese manufacture, which criminals obtain to use in such illegal activities as terrorist attacks and narcotics operations.(2)

While most lasers found outside of research laboratories or medical/industrial facilities cannot penetrate metal or even damage skin, the eye remains vulnerable. As laser light passes into the eye, it becomes focused by the cornea onto the retina. Located at the back of the eye, the retina is a layer of living cells that intense light (by causing highly localized heating of the area) can damage or permanently destroy. The actual effect on the eye will vary with the power of the laser, the length of time the laser remains trained on the eye, and the portion of the retina that the focused light impacts. The effect of looking into a laser beam can range from true blindness, to dazzling (similar to closely viewing a camera flash), to annoyance. In many cases, the effects will not last long, perhaps only several seconds to some minutes. Also, temporary irritation or the presence of afterimages (visual sensations occurring after the external cause has ceased) could last several days but eventually should disappear and cause no further problems.

While lasers can cause a variety of visual impairments, the dazzle effect represents the greatest threat to law enforcement officers and could constitute a critical distraction in a tactical situation. The reaction to dazzle has both physiological and psychological components. Experts do not entirely understand the relationship between these two aspects. However, sudden exposure to dazzling and overwhelming light tends to startle some individuals. Sometimes an immediate, though temporary, loss of vision will occur. Functional vision loss can happen either because of the biological action of the eye to direct light or because of indirect glare caused by reflections from other objects.

These visual distractions of the dazzle effect prove more powerful at night because the pupil becomes dilated and allows the greatest amount of light into the eye. The dark-adapted eye becomes more sensitive to the effects of light stimulus. Therefore, the dazzle effect occurs when a bright light overwhelms the eye as a sensor. The effect can become worse if the light passes through a visor, windshield, or other transparent lens. If the transparent material is dirty or scratched from use or age, the effect becomes more pronounced and, therefore, more effective in obscuring vision. Further, viewing a laser through magnifying optics increases the potential to damage the eye and places officers using binoculars or magnifying scopes at greater risk)

Such a laser use could cause mission failure, allow suspects to escape, or if used on officers while driving a vehicle or piloting an aircraft, cause a loss of control, which could lead to injury or death. Moreover, in tactical situations, affected officers could become targets for suspects armed with lethal weapons.

Lasers and the Police Response

In a recent report, a university detective referred to an incident during a crowded student activity where a red dot appeared on the chest of a security officer. The detective stated. "From a police perspective, laser dots are usually attached to firearms. Seeing a laser dot outside of [a] classroom obviously caused us great concern."(4) Because they associate lasers with firearms, officers illuminated by even a laser pointer may respond by drawing or even discharging their service weapons. If officers draw their weapons, then perpetrators may respond in kind with the same ultimate end: fired weapons. An even worse scenario involves youths playing with laser pointers not realizing the potentially dangerous situation they could initiate with police. Therefore, police departments should consider developing a tactical laser defense plan and training officers in how to minimize laser threats.

First, laser eyewear protection represents an effective hardware countermeasure, but it has some severe limitations. For example, protective eyewear guards against only specific colors and laser power levels; therefore, officers must know the type of laser employed against them. Also, protective eyewear costs over $100 per pair, is uncomfortable, prone to fogging, and may skew normal color perception, And, finally, officers must wear the eyewear prior to any engagement where laser use could occur.

Most important, officers should know that no clinically accepted treatment for laser-related eye injuries exists at the present time. While it may seem judicious to evacuate known laser-related eye casualties, officers must evaluate the tactical situation prior to doing so. Neither the affected

officers, nor members of their team, should expose themselves to other risks for the sake of evacuation.

Additionally, annual or less frequent training should emphasize probabilities of encounter, biological effects, and understanding the biological and psychological responses (particularly for pilots and drivers) caused by lasers. Departments should develop competent technical resources - such as local military, university, industrial, or medical laser consultants - who could train their officers or, on short notice, assist with special missions. Also, departments should modify their rules of engagement to include specific criteria for evaluating laser threats.

Conclusion

The rising trend in laser use, whether legitimate or criminal, warrants careful consideration by law enforcement officials. Currently, lasers have a fear factor that may exceed their actual hazards. However, law enforcement agencies should understand that even a small threat can cause grave consequences to uninformed officers.

Because the greatest laser threat environment occurs at night and primarily to aircraft or vehicle operators, officers in these situations must receive information about the dangers associated with laser usage. Agencies should evaluate the potential of laser encounters in their jurisdictions and implement basic laser defensive instruction as part of an existing training program. Educating the law enforcement community about such new potential hazards as laser threats remains the most effective method of protecting officers from forms of technology developed for society's enhancement but often exploited for malicious purposes.

Reporting Lasers Used in Crimes

Because some states may not have a reporting category for lasers used in the commission of a crime, Texas A&M University, in conjunction with Walter Reed Army Institute of Research has developed a Website to collect this type of report for statistical purposes. The U.S. Army Medical Research Detachments Automated LASER Accident/Incident Reporting Website at http://hoxie.brooks.af.mil/. LASER has a concise, easy-to-use Automated LASER Accident/Incident Report form for officers to submit factual accounts of lasers used in a criminal manner. Information collected includes lighting conditions, color of laser, description of the effects on the eye, and several other categories. To gather as much information as possible, all law enforcement officers are encouraged to submit laser incidents to the Website. In time, the results will be compiled and available online. Officers can direct questions to Douglas Johnson at [e-mail].

Endnotes

1 The word laser was originally an acronym derived from light amplification by stimulated emission of radiation.

2 Jane's Defense Weekly (May 18, 1995) 3.

3 Questions have arisen about the effect of lasers on night vision goggles. Laser light cannot harm the eye if it first passes through the goggles. What the eye sees is a processed signal, not the actual light environment. How vision is affected will depend on the specifics of the laser and the technology incorporated into the goggles. A possible range of effects varies from temporary saturation of all or part of the viewing field (temporary failure) to permanent burnout of a portion of the viewing field.

4 Information obtained from Detective Sergeant David J. Villarreal. Texas A&M University Police Department.

A Reserve Navy Lieutenant Commander assigned to environmental health matters, Mr. Johnson serves as the laser safety officer for Texas A&M University in College Station, Texas, and sits on the American National Standards Institute for Laser Safety committee.