Police hat

The  is a piece of clothing found in the Fallout 3 DLC Broken Steel.

Locations

 * In the Presidential Metro, by a skeleton on a bench near some of the tracks. To find this is easy, after you exit Margot's control room you will see an American Flag, go that way and turn left towards the tracks, while facing the tracks make another left. Go towards the caved in part of the tracks, and near the wall you will see a skeleton with a .32 Pistol and a Police Hat.
 * After you exit the hall with a few flags and the statues of presidents immediately turn right, it is on the bench there.
 * One is also located in the office with the safe in the Old Olney S. Wilson Building on the floor.

Appearances
The Police Hat is contained in Fallout 3's game files but is not actually used in the game (this adult version at least; Knock Knock wears the child version). Several Police Hats can be found in the Fallout 3 DLC Broken Steel.

I, Final Witness have confirmed that if you type "player.TestQAItems" into the console (PC version) you will be teleported to a room with every item. One of which being a Police Hat- This could be from the Fallout 3 Game Files!!!