Too much of a terrible thing
I felt the use of crime scene photos was overkill. The director had a Q&A session after the film was screened, and claimed that the movie, including the use of photos, was all meant to evoke emotion. That is exactly what happened (however unfortunate) as three people left the theater after "hearing" the last bullet being fired.
I thought all the photos, being shown over and over again, was unnecessary. I've seen powerful, moving documentaries, that stirred up much more emotion in me, without using so many disturbing photos. This film just made me feel rather unsettled and disturbed, which is not the best emotion to feel even when watching a documentary dealing with this type of subject matter. I was not the only person in the theater that had to look away more than once.
Unfortunately, this part of the film (photos) is ingrained more in my memory than other, moments, such as the survivors talking about their lives after the tragedy, and stories of how their relatives found out.
"If life is enjoyed, does it have to make sense?"