"I have never seen anything that messes with the eyes like the strobe. It is a fighting tool," says Louis Chiodo in "The Snubby Revolver" by Ed Lovette. "It can help the officer get inside the suspect's OODA (observe, orient, decide, act) loop. If the suspect is at the top of the loop (observe) when the officer uses the strobe and the officer is at 'act,' the strobe can disorient the suspect long enough to buy the officer the extra time he needs to control the situation."
— Reprinted with permission from the author.
At its most basic definition, strobing is using a handheld flashlight with a flashing feature to gain a tactical advantage over a suspect. Strobing disrupts a subject's balance, short-circuits his perception, causes him to look away and induces mental confusion.
Because of its powerful tactical effects, strobing has gained a strong foothold in law enforcement. These new, powerful and efficient flashlights with advanced circuitry (See "Strobing lights" on Page 10.) have even created a unique vocabulary among officers, who are now heard to utter things like, "He strobed," "I strobed" or "He strobed while I moved up."
Louis Chiodo, who as a firearms instructor for Chula Vista, California-based GUNFIGHTERS Ltd. has trained personnel from approximately 95 national and international police agencies, says strobing affects a person's ability; it gives them different perceptions. He emphasizes the greatest benefit a strobing flashlight can provide is its ability to "open up doors." His low-light classes at GUNFIGHTERS Ltd. help participants capitalize on the momentary disorientation strobing provides. During his training sessions, one easily recognizable trend is the close quarters advantage of the strobing light.
Strobing also can be used to prevent the subject from certain areas or routes of escape. Officers who form a perimeter after a pursuit can channel the anticipated route of a suspect to a more desirable one by strobing an area of denial.
Officers can also exploit the momentary short-circuit caused by strobing. For example, when the suspect is frozen momentarily in time, the officer can order him to "slowly point out the location of any other suspects/weapons in the car." This short-circuit, plus verbal stimuli may produce a useful response.
The science of strobing
Strobes have been installed in residential and commercial alarm systems for decades. These systems are known to cause mental confusion and a sense of immediacy, as well as short-circuit the decision-making process. When combined with the piercing sound of an alarm, strobes are effective at removing personnel from an area. The military also has experimented with using strobe lighting "to disorient and confuse personnel" and reduce collateral damage.
But not all of the effects of strobe lighting have been completely explained. It is known that the human brain prefers continuity in order to process information. If the stimuli from different senses seem incongruent, it causes confusion.
Scientists have determined, unlike eyes in animals, the human eye is incapable of detecting motion. Motion is perceived by the human brain and not from sensory input to the eye. Because of this, human perception of color and motion rely on the brain's ability to decipher smooth regular motion. When perception input arrives in segments, the sensory information received by the brain is confused.
Any light source that overloads the photoreceptors in the eye will produce an afterimage, sometimes called persistence of vision. This can occur in two phases: The first phase arises from the immediate discharge of the photoreceptors, the second from a loss of sensitivity. Both produce afterimages. Persistent images alone can short-circuit the brain. Strobing tactical lights work because they do not allow the photoreceptors to reset, which shocks an individual's vision.