Book I, and AI, cant seem to find

Im looking for a book, I believe the title has something to do with "chaos" the premise is this school teacher who comes home to find out that he is being framed for a crime, I believe murder, that he didnt commit. He ends up hiding out in some hills behind trails in a neighborhood whilst living in a tent. He only has a bit of cash and he ends up turning to, I believe, his ex girlfriend for help, she helps him with some cash and they end up getting back together in the end. He ends up finding this old grizzled private investigator who is willing to help him and together they end up clearing his name.

Any help would be greatly appreciated. Tagged spoiler due to explanations of the plot and ending.