Police officer does have a few differences between standard 501st admission and MEPD deployed status. SWAT status is even more and VERY detailed. Certain pieces need the "return" edge which does make them look thicker. Mostly the body pieces. leg pieces, and a little on the top of the bicep have some return edge, Check out pandatroopers build thread, it'll answer this better than I can state it.
Stamdard strips are 15mm for arms and 20-25 for legs, but these vary trooper to trooper as the armor does have to fit you. I'd concentrate on getting the raised areas at the but joint (when placing two pieces together) to be roughly the same width as the cover strip. Then you work out the remainder to fit in the back. where you may need wider cover strips. I'm using 17mm for arms and 22 for the legs. And yes, you can make them fit you and still get approved.
Lots of more knowledgeable guys here than me, but this is my take on it.