No Rest for the Dead by Jeffery Deaver

When Christopher Thomas, a ruthless curator at San Francisco’s McFall Art Museum, is murdered and his decaying body is found in an iron maiden in a Berlin museum, his wife, Rosemary, is the primary suspect, and she is tried, convicted, and executed. Ten years later, Jon Nunn, the detective who cracked the case, is convinced that the wrong person was put to death. In the years since the case was closed, he’s discovered a web of deceit and betrayal surrounding the Thomases that could implicate any number of people in the crime. With the help of the dead woman’s friend, he plans to gather everyone who was there the night Christopher died and finally uncover the truth, suspect by suspect. Solving this case may be Nunn’s last chance for redemption…but the shadowy forces behind Christopher’s death will stop at nothing to silence the past forever.