Just a heads up, you CANNOT unlock this in Story Mode. It has to be done in Serial Killer mode.
This earliest you can unlock this is Chapter One, the Prologue doesn't count. This achievement is overly difficult thanks to the game's awful controls and the Zodiac's ability to see/hear you from across the map.
Best advice I can give is make liberal use of crouch and lean to watch the Zodiac and then run with Left Trigger the second his back is turned to get to your next hiding spot. If he does spot you RUN as far as you can to a hiding place and hope he forgets about you.