What are the ways in which O'Brien develops the characters in In the Lake of the Woods?

O'Brien uses an interesting technique that moves through
time, giving us clues about the characters, but never enough information to know exactly
who did what at any one time in the novel ... including the ending.  He introduces us to
characters in much the same way we find out about the people we live with.  We never sit
down with someone and query their life story.  We find out bits and pieces about people,
often the most trivial with the really significant information evolving only through
time.  O'Brien wanders through time, offering possible interpretations (which can be
confusing since we often forget that much of what happens in those chapters is
conjecture and not "fact.")  For instance, we know that John and Kathy's lives are a
disaster, but we don't know why.  We find out that he lost an election that he was
leading, but we have no idea why.  Bits and pieces of evidence from different time
periods surface during the evidence chapters, not only from John's life span, but from
prior periods in history.  The reader gets a sense of putting the characters' lives
together as the pieces are presented ... the author provides the information, but we
assemble the "pieces."  I don't know if this would work for other novels, but I think
O'Brien did an interesting job with it in this novel.