The Sweets of Doom by Wendy Meadows

An amateur sleuth in a small town, and a respected school teacher found dead… Will Margaret bring light to his murder and find the killer?

The entire neighborhood is shaken when their friend and respected school teacher, Jose Santiago, is found dead by his teenage son, Michael. That’s not the only unnerving threat hitting the streets recently, Margaret has been getting wry letters taped to the door of her candy store. Her son, Zach, and Detective David Graham don’t think it’s a coincidence as an investigation to find the killer gets underway.
Dark details of Jose’s murder come to light as the cause of death was cyanide poisoning, with markings of a local coven found around the crime scene. Suspicions fall on the local ‘witch’ coven, making them the primary suspects.
Michael hires Margaret to try and track down his father’s murderer, with David begrudgingly accepting her help on the investigation to keep an eye on her.
As more cryptic notes are left, along with lousy misfortune hitting the residents – this cozy town soon dissolves into a ghostly version of a frenzied Salem in 1962. Paranoia stands on every corner and the bad luck and backlash quickly turn a friend to foe – to a killer.