Knockdown by Sarah Graves

Sarah Graves sets her mystery, Knockdown, in Maine, a perfect location for fog, old houses and small town mentality. Jacobia (Jake) is handy at wielding a hammer or paint brush and along with the mystery are home repair tips.

From the Cover:
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 unsettling 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. . .