Something I didn't understand.

During the interrogation of the two white officers, they state that their guns were checked and that no one has been issued a gun (or perhaps just not issued the ammo) that was used in killing Waters. This made Taylor and Davenport very upset. Taylor thought that it proved their guilt because they were lying. Davenport felt like this knowledge was kept from him for some purpose of deception by Colonel Nivens. The type of weapon used not being issued to some men would seem to me a way to exonerate the white men. Why wouldn't Nivens offer that info quickly to prevent any issues with Davenport? And since the type of weapon used was never bought up until that moment, it seems weird for Taylor to think they were lying about it to cover themselves.