If you can find all 20 of these badges, the dapper Button Man suit will be unlocked which provides extra ammo for all weapons. Each badge also provides 5 additional XP which will help further unlock intuition points.
L.A. Noire Police Badges Locations Guide
You can find these badges by searching in the specified locations below.
Police Badge #1
Location: Grauman’s Theater
Face the theater, you will see a large red carpet with two small red carpets on each side of the entrance to the theater. Search the left small carpet and you will find the badge.
Police Badge #2
Location: Hotel Roosevelt
Search the front door area of the street to find this badge.
Police Badge #3
Location: Max Factor Building
Take the car through the fenced in area and you will find the badge lying on the ground near the dumpster.
Police Badge #4
Location: Musso And Franks
In the parking lot in the back area under the green overhang entrance.
Police Badge #5
Location: Crossroads To The World
From the main central area, walk forward towards a small path that leads to the other side. This badge is lying on the same path.
Police Badge #6
Location: West Lake Tar Pits
On the porch of the small white building by the tar pits.
Police Badge #7
Location: LA County Art Museum
Facing the front of the museum, take right to the Staff Parking area. From the building, take a left down a thin hedge lined path that leads to a metal staircase. The badge is lying on this staircase.
Police Badge #8
Location: Bullocks Wilshire
Inside the Atrium, take the stairs down on the left, and you will find the badge at the bottom.
Police Badge #9
Location: Intolerance Set
Get inside by driving your car through the gate. Take the right hallway, turn left, and go down stairs. You will find the badge on the narrow hall.
Police Badge #10
Location: Macarthur Park
On a barrel by the paddle boats.
Police Badge #11
Location: Los Angeles Examiner
On the corner of a planter on the back left of the building.
Police Badge #12
Location: Rko Theater
Lying on n the ground at the main entrance in front of a movie poster.
Police Badge #13
Location: LA Public Library
Climb a pipe at the backside of the building, and get on the scaffolding to get to the main roof area. Take left and you will find two large cylinder tanks on both sides of the platform. Jump on the platform to find the badge.
Police Badge #14
Location: Pershing Square
On the table beside the railway car diner. (Old railway car turned into a diner).
Police Badge #15
Location: Hall Of Records
On the right side of the reception desk inside Hall of Records.
Police Badge #16
Location: Union Station
From front door, take a left. You will find it on the third ticket booth from the right.
Police Badge #17
You will find it between two statues in a narrow alley in the far west side of Chinatown.
Police Badge #18
Location: Angels Flight
Under the tracks on the bottom side of Angels Flight.
Police Badge #19
Location: 6Th Street Viaduct
Go underneath the bridge, and at the canal there is a center support with a ladder. The badge is on top.
Police Badge #20
Location: Main Street Terminal
Infront of the red subway car up on the tracks.