Dirty cop Achievement - Call of Juarez: The Cartel
Immediately after taking the zip line, it's by the van.
Shortly after the previous secret item, there's a small village up the road with a few houses. It's in a house near the water tower.
In the same village, it's outside one of the houses on a barrel.
After the 2 fist fights, on a table at the bottom of the stairs.
As you run from the gangsters, you'll get held up in a house for a quick shootout. There are 2 special items in this house. Wait till you finish the gunfight for your teammates to leave so you can steal them secretly.
After jumping from cover to cover, you'll run down some alley ways. It's in a building on the left.