Crackdown

The Los Muertos area is the first section of the game that you will play. This achievement requires you to only find them and you do not need to confront or kill them to add to this achievement.

There are seven gang bosses (dossier targets) altogether which can be seen on the map i have provided. Once you have visited the last boss the achievement will pop straight away and you will also receive an XP bonus.

Click here for map