What is the author's tone in Dead Man Walking: An Eyewitness Account of the Death Penalty in the United States by Helen Prejean?

The book covers the executions of two convicted murderers, both who claim they didn't play the role of which they'd been accused. Helen relates the agony of waiting as the two men prepare themselves to meet death, knowing the exact time, place and method of their deaths. There is a sense of helplessness and hopelessness about the story that can't be hidden behind words of peace and forgiveness, and the author doesn't really try to overcome that sense of despair.