This trophy takes place during the Release story mission, the very first mission in the game. In fact, it will be the moment you first take control of Faith. You need to complete the very first section of that mission by walking (not running) until you get out of the main gates of the prison and into the parking lot. The walking speed is very slow and the controls are very sensitive as far as switching from a walk to a run, however the game seems to let you slip up a few times and still give you the trophy.

If you missed this trophy, you can always replay the first mission by pressing , then pressing  twice to move to mission select, and then selecting the "Release" mission.