Knockdown : a home repair is homicide mystery / Sarah Graves.

Enhanced descriptions from Syndetics:

They say you can't go home again--and when it comes to someone with an old score to settle, sometimes you'd better not. That's what Jacobia "Jake" Tiptree discovers when the past she thought she'd laid to rest comes calling at her lovingly restored 1823 Federal-style house in Eastport, Maine. Unfortunately, her old life and her new one are about to collide with deadly consequences. . . .
 
Jake is deep in her latest home improvement project--repainting a porch--when she notices the man repeatedly biking past her house. His face is unsettlingly familiar, but his chilling message seems inexplicable: Blood shows up again. Murder will out.

If it's a prank, it's an ugly one, and so is the anonymous email warning her to beware the Fourth of July--just two days away. Back in her days as a hotshot financial manager she did business with plenty of shady characters, but she's still baffled as to the identity of her nemesis--until she receives a photo of a murdered man.

Now Jake knows what--and whom--she's up against. But knowing her enemy is no guarantee that she can escape the grim payoff he has in store for her. From home invasion to kidnapping, this twisted killer is slowly but surely plotting a knockdown with not just Jake but the entire town of Eastport at its explosive center. And no one can predict when or where the shockingly deadly finale will occur.