Bits and Pieces by Annette Mahon.
I was lucky enough to be one of the recipients of the ARC of this book, the third book of the St. Rose Quilting Bee mysteries, whose protagonists are the members of a church group for the retired. Most of the story is told from the point of view of Maggie Browne, a widow with four (if I remember correctly) adult sons, one of whom is a police officer.
The story begins when Maggie receives a phone call from one of her friends and Bee compatriots, Clare Patterson, who believes she has spotted a wanted felon in their local big box store. The young man she thinks she's seen is Kenny Upland, a veteran suffering from PTSD, whose wife and twin daughters were killed when their home exploded six months earlier. Kenny had been off on a solo camping trip at the time, and when he was not found in the house's rubble, the consensus was that Kenny had killed them as a result of some trauma-induced hallucination or nightmare.
Maggie calls 911 for Clare, but Kenny leaves the store before the police get there, and Clare follows him up a mountainous road, where she has an accident.
When she returns home, she insists that Kenny Upland saved her life, that he's innocent, and that it's up to the Quilting Bee members to clear his name.
Through a fascinating combination of common acquaintances, Google and "little grey cells", the women manage to determine the identity of the true culprit.
I don't know how the earlier entries in this series slipped past my radar, but I'm going to have to rectify that error.