Novel where a woman goes back to her hometown, where her mother was stoned to death

Question

Somewhere around 2010, I was riding an Amtrak train when we had to be diverted to a bus due to a train derailment ahead of us. Because of the extra delay, people started running low on reading material, so an informal paperback exchange ensued. The one I wound up with followed a woman who was returning to her hometown, I think to solve a crime. While there, we learn that her peculiar habit of picking up rocks and putting them in her pockets is legacy of a past trauma where she saw her mother stoned to death in her front yard by the people of the town, a crime for which I believe no one was ever charged (and I can't remember what it was that the mother had done that led to people stoning her). For some reason, I want to say the title was something like "Concrete Angel", but the books I've pulled up under that name don't seem to match plotwise. I also don't remember if the crime she was investigating wound up being tied to her mother's death.

My memories are vague at this point, but I'm pretty sure that the story was set in the United States, and that the protagonist, and her mother, were Caucasian. And I think the cover was mostly black, maybe with a picture of that angel. Past that, I can't recall the details.

Answer 1

I could have sworn I'd done sufficient searches, but of course, shortly after posting my question, the right search terms came to me. novel mystery angel "stoned to death" brought up Stone Angel by Carol O'Connell, fourth book of the Kathleen Mallory series.

Seventeen years after her mother, Dr. Cass Shelley, was stoned to death by an angry mob in Dayborn (La.), Kathy Mallory, who fled the scene to become a New York street kid and, eventually, an NYPD sergeant, is back to find out who provoked the mob and what became of her mother's corpse. Since Mallory is Mallory, she's in town less than an hour on All Saints' Day when Ira Wooley, an autistic savant who was the world's most unreliable witness to the killing, has his hands savagely wounded; Deputy Travis, who's never told everything he knows about the killing, has his chance to talk cut off by a massive stroke; Babe Laurie, the revivalist who'd be a leading suspect if ancient cases had suspects, has been murdered; and Mallory is sitting in the pokey, thumbing her nose at dogged Sheriff Tom Jessop and lecturing acting deputy Lilith Beaudare about how to stand up to her boss. Mallory's loyal friend Charles Butler, following her down from the city with the idea of helping her out, naturally remains a consistent two leaps behind her, though he does get to spend time with some flavorsome locals—manly spinster Augusta Trebec, mute sculptor Henry Roth, enterprising innkeeper Betty Hale (who's turned the stoning into something of a local holiday), and the rest of the equally nasty Laurie clan- -en route to a dizzyingly complicated windup involving spiritualism, child abuse, and good old-fashioned greed.