The Enforcer drops a blueprint upon being killed and the blueprint dropped will give you that exact enforcer you just deafeated. It will have the same color(s) and stats as the one you killed and can be crafted at any city terminal. The higher the stats the more ingredients you will need.
For a basic enforcer, go around the city and gather at least 500 element dust from lampposts(preferably more), kill a few isolated enforcers until you get 20 oil, go to the wasteland killing the weaker corrupted creatures for corrupted nodules (they can be used as polymer)
When you collect all the resources, go to a city terminal and craft your own enforcer.