For the collectible map for this district, refer to this page.
On the pillar in the basement of Sammy’s Bar, the same room where you can find your Safe and an issue of Playboy.
Near the entrance of Perla's, on the wall behind the counter to the left
In the wall inside the office of Merle Jackson’s office, second floor of Perla's
Inside the office inside the building beside the church where the heroin are stored. (Also accessible during the story mission: The Way of the Flesh: Smack)