Dr. Cassi L. Fields’ has written for quite a few Fire and Police related magazines. Here is a sample from an article published in Police Chief Magazine:

One of the most challenging aspects of using promotional exams in public safety departments is ensuring that the process is valid and produces a diverse group of candidates. Further, the prevailing legal guidelines and court rulings make it more difficult for a law enforcement executive to make selections from a valid test if those selections result in adverse impact. Since the inception of the 1964 and 1991 Civil Rights Acts, court decisions with regard to employment discrimination have added to all test users’ burden to defend its testing processes. The current rash of employment discrimination lawsuits in public safety selection and promotional exams proves this point.
Many observers of these cases have experienced the frustrations that led to litigation—namely, “How do I use a promotional test and not get sued for adverse impact?” or “What strategies can I use to ensure the diversity of my workforce while avoiding lawsuits for civil rights violations?” Many police chiefs have experienced the feeling of being between a rock and a hard place when implementing selection or promotional systems.