What is the tone of the Benjamin Fraser poem?

In Spoon River Anthology Benjamin Fraser is the son of Daisy Fraser and Benjamin Pantier. Both parents were embittered outcasts in Spoon River. Daisy was evidently a prostitute, and Benjamin Pantier was a man stuck in a bad marriage, eventually thrown out of the house by his wife, who could not stand the sight of him.
In Benjamin Fraser's soliloquy, it's difficult for the reader to know explicitly what he's talking about, as Masters apparently intended. The tone is defensive but also implicitly apologetic. One interpretation is that the thousands of spirits beating upon him are those of people he has murdered and of women he has raped. Benjamin refers to both his "ecstasy" and his "torture," saying that "they" looked wide-eyed at his "starry unconcern." There is a muted horror he seems to project about his actions, but at the same time, his tone is that of a sociopath. He does not appear to suffer any genuine sense of guilt, though the entire monologue indicates a kind of befuddled suffering as he is condemned to this "wingless void" where his soul resides.
Throughout Masters's epic work, the personages of Spoon River all express a haunted resignation over their fate and that of the others. Benjamin Fraser is no exception.