Call of Juarez Bound In Blood: Chapter 4 - Secrets

The first secret you will find next to the white arch (it is hidden in the chest).

The second one is located in the place, where you have to attract snipers' attention playing as Ray (in the chest, under the roof).

Of course you can get that secret playing as Thomas as well, but you have to return for it after dispatching snipers.

The next one is placed in the central part of the market, next to the weapon store (under the roof, in the chest).

The last but one in the place where you can find a goat. It is near the open space area at the front of the church (the scroll will be on the bench, not in a chest).

The last one is inside the church, in the side nave. Take it before you will start Cooperative Concentrate Mode.