Flashlight guards are enemies that appear in all four games of the Sly Cooper series. As their name suggests, they patrol the ground and use flashlights to help them see. All have some kind of projectile weapon, like guns or throwing knives. In Sly Cooper and the Thievius Raccoonus, flashlight guards can be killed with one whack of Sly's cane. These guards' attacks never miss unless blocked by some object, like a wall.
In Sly 2: Band of Thieves, flashlight guards take multiple hits to be killed. When hit, they are knocked back but will immediately kick and shoot their weapon. The kick attack can be avoided if far away enough, but the gunshot is extremely accurate. At very close range, they will attempt to damage the player with a melee attack. In Sly 3: Honor Among Thieves, flashlight guards will not be knocked back, allowing more damage in a shorter time. In Sly Cooper: Thieves in Time, the guards attack after they are hit twice. Because they usually take more hits to defeat than rooftop guards, flashlight guards carry more valuable loot.
Sucker Punch called flashlight guards "smart guards" during the development of Sly Cooper and the Thievius Raccoonus.
There is a removed flashlight guard who was supposed to be in Raleigh's stage, but got cut. He carried a bow and arrow and his victory dance would have been him spitting green goo on the ground.
According to audio from the demo disc for Sly 2: Band of Thieves, a new type of flashlight guard would have been introduced in the job "Theater Pickpocketing." These guards would have had red flashlight beams, and they would have all been in radio contact. Being seen by one would have alerted all of them.
In Sly 3, flashlight guards on higher ground can occasionally be seen jumping off bridges to get to the ground level. This will most likely happen when the guards are chasing the player.