One of the things I've noticed with crime series, is that the corpse often arrives later and later in each book. It's as if the writer knows the reader trusts them: that it'll appear eventually, and are happy to go along with plots and characters and motives being not just established but explored, meanwhile.

Emma

That's interesting. I've never noticed that. I'll keep an eye out for that. Funny how you don't see these things until someone points it out...

Also of course, with crime you don't necessarily care about the corpse - it's the detective who is the focus of our attention.

In order to make the reader side with the investigator, you do. A lot of modern forensic detective stories work things backwards, by bringing to corpse back to life through the investigation. I think at some point, for a crime thriller to work, the reader has to feel the victim is, or was, believably real.