I haven't read this one yet, but noted some great comments by other members.
I nominate, Thin Blood
by MR member author Vicki Tyley. Available at smashwords.
A stockbroker’s wife disappears. Blood on his hands and an adulterous affair with the missing woman’s younger sister sees him charged with murder. With no body and only circumstantial evidence he walks free. Ten years later, journalist Jacinta Deller decides to investigate, only to become embroiled in a warped game of delusion and murder.