Change a full color image into a three color half tone image

A project came in and a full color image has to be changed into a three color half ton image. I selected tri-tone and selected the three specific colors, but it don't look like i'm getting the half-tone effect; meaning that the client wants to see the dots.

Ideas?

Idea

Thanks! 

  •  The half-tone effect is usually generated in your Print Separations tab in your Print Dialog. You have the ability to set your screen frequency and angle and all those goodies that pertain to halftoning.

    There is a halftone filter under effects that simulates the 'dots' but it will not be a true representation.