Evidence, by Jonathan Kellerman

I really have enjoyed all of Kellerman's stuff over the years. Jonathan or Faye? Yes.
Evidence seems to be a return to the earlier style of Milo and Alex just working their way through a very difficult and twisty case, without a lot of danger involved, more or less a police procedural novel.
Two people are murdered in an abandoned construction project in an upscale neighborhood, their bodies left in a sexual pose. The man was an architect, who had nothing to do with this project, but had worked for a Green avant-garde design agency, while the woman, at first, is unidentified.
As Milo and Alex begin to dig deeper, the trail of evidence leads them all over the place. The woman turns out to have been an FBI confidential informant on the subject of ecoterrorism, and eventually they find a past connection between the two victims. The mansion under construction turns out to belong to a middle eastern royal, and Milo and Alex rattle a few diplomatic cages along the way. Not long after the initial crime, an unknown arsonist burns the crime scene to the ground, killing another apparently innocent bystander. Thinking there's a connection to the inital crime, the two hare off on that rabbit trail next.
Ultimately, the book solves three separate mysteries, and is pretty good entertainment. The only disappointment is that only one of the mysteries gets a tidy wrap-up, and the others are left with a few dangling ends, questions unanswered. Perhaps this is closer to the reality of true crime than the usual novel.