Disguised weapons come in all shapes and sizes and may be found under any circumstances, in the possession of persons of all ages, races, or social status, and both sexes. The most common type of disguised firearm is the pen gun, a term applied to a weapon which is disguised to look like a pen or to any single-shot firing device of tubular appearance. Another popular disguised weapon, the cane gun, contains a hollow metal barrel. It comes in various forms, including the tire iron shotgun or the handlebar gun. Disguises that have been used to hide weapons include cigarette lighters, cigarette packages, belt buckles, and wallets. The assassination kit, a specially fitted attache case, is a prime example of a concealed weapon. The officer must be aware of the possibilities of disguising weapons, but must maintain perspective and exercise judgment in protecting himself. X-rays may not detect nonmetal weapons. Officers encountering disguised firearms should seek advice from ordnance specialists, or the Bureau of Alcohol, Tobacco and Firearms. Weapons other than firearms -- blackjacks, brass knuckles, or cutting devices -- may also be concealed. A discussion guide presents the significant elements of the U.S. Supreme Court decision in the case of Terry v. Ohio as it applies to the stop-and-frisk.