Every officer knows that a duty flashlight is for much more than looking into cars (though that’s a critically important purpose). A high-performance flashlight also affords a significant advantage during an encounter with a subject in a dark environment — this is known as defensive illumination. While light clearly cannot fully control a subject, a flashlight with a high-intensity central beam can create a protective “wall of light,” giving the officer a tactical edge.
Shining a bright light directly into a subject’s eyes obviously has multiple benefits—it greatly reduces or even eliminates their ability to see, while increasing the officer’s. And it minimizes or eliminates the risk of the officer being silhouetted. Once a threat has been identified, ensure that your light remains on and is kept shining in your subject’s eyes. This will put you in a controlling position, while protecting you behind that wall of dominant illumination.
That being said, while the wall of light is a powerful tactic, there are times when there is such a thing as too much light. For example, when clearing small rooms—especially those with white or other light-colored walls—light reflects back towards the officer (appropriately called backsplash), and can significantly impair his or her vision. So it’s important to have a light with a second, lower light level option, and/or a smaller everyday carry (EDC) type for close up/indoor/small space work.
My favorite flashlight, and the one that’s become my primary lighting tool on the job, is the ASP Pro DF. This rechargeable/dual fuel light is small enough for everyday carry, yet powerful enough for duty use. It has a bright enough main beam to give me that wall of light advantage, but also offers a programmable secondary level, so I can quickly drop down to a low setting when working indoors or up close. Yet even with this versatility, I still carry a backup light—actually two—because nothing is foolproof. Equipment breaks or gets lost, batteries die when you least need them to—and no officer wants to be left in the dark during a critical encounter. As we say in our flashlight training courses, “two is one, one is none… and none is stupid.”