I once held a civilian, administrative position within a police department and know from that experience that the background investigation for any potential police officer is extensive. I do not know what the policy is on hiring an LEO with PTSD but I do know that if you do not disclose your PTSD they will find out anyway. Among other things, our background investigations included detectives talking in person (face-to-face) with the applicant's family, friends, neighbors, past neighbors, past employers, past co-workers, etc. I think it extremely unlikely that they would not discover your PTSD. You definitely would want that information to come from you and not be uncovered by an investigator.