Miagani Island: Militia Shields
Found on the east-facing side. You'll have to drive under the bridge to spot it.
Ranelagh Ferry Terminal
On the east side of Kingston, on a building across from the terminal proper.
Bank of Gotham
The bank is found in central Kingston. You'll have to get a good distance to see the shield hanging high on the building.
Hanging above a Koul Brau storefront.
Found high on the Ferris Mall building.