SPOILER ALERT!
Witness in Death [J.D. Robb]
This one's a little odd, everyone had motive and the murder was on stage in front of hundreds (thousands?) of people, including Eve. I don't think I'm going to have that much to say about this one.
This is another one that I didn't really remember, so I wasn't sure who'd done it or why. Eve figures it out, but it doesn't become clear until the murderer says that they were the one to kill Richard Draco.