If I'd Killed Him When I Met Him...

Description for IF I'D KILLED HIM WHEN I MET HIM... by Sharyn McCrumb:

When forensic anthropologist Elizabeth MacPherson becomes the official P.I. for her brother Bill's fledgling Virginia law firm, she quickly takes on two complex cases. Eleanor Royden, a perfect lawyer's wife for twenty years, has shot her ex-husband and his beautiful late-model wife in cold blood. And Donna Jean Morgan is implicated in the death of her Bible-thumping bigamist husband.

Bill's feminist firebrand partner, A. P. Hill, does her damnedest for Eleanor, an abused wife in denial, and Bill gallantly defends Donna Jean. Meanwhile, Elizabeth's forensic expertise, including her special knowledge of poisons, leads her into the most challenging case of her career....

This is #8 in An Elizabeth MacPherson Mystery.