Living Witness.  By Jane Haddam.

Series mystery.  Detective: Gregor Demarkian.

A near-fatal assault in a Pennsylvania small town appears to have been triggered by a lawsuit over intelligent design and evolution.  Gregor Demarkian is called in because the town police chief is a possible suspect. 

All of Jane Haddam's mysteries have a secondary subject - or maybe a primary subject, and the mystery is the secondary bit.  This one  looks at intelligent design, religion and class in American society. 

Haddam mysteries tend to be low on action and high on commentary.  That's part of their appeal, because Haddam is literate and intelligent and often quite funny.  That being said, there is perhaps too much commentary in this title.  It swamps the story sometimes. 

Living Witness is, as we say, recommended for fans of the series.  That means you probably won't enjoy it so much if you're not a confirmed Haddam fan.  Cheating at Solitaire is a much better book.