Kaleidoscope : a Joanne Kilbourn mystery / Gail Bowen.

Enhanced descriptions from Syndetics:

The thirteenth in Gail Bowen's beloved and award-winning Joanne Kilbourn mystery series promises to be the best of them all: some very bad things happen very, very close to home, and Joanne may never be quite the same again.
 
"Security for any one of us lies in greater abundance for all of us." For many years, this was the core of Joanne's political beliefs, but for a number of reasons, she has drifted away from it. But on the day Joanne retires from her university teaching post, she has a dream about her first husband (murdered many years ago), and this line comes back vividly in it.
 
Soon, she is forced to experience the truth of what, for most of her life, had just been a good closing line for a political speech. The night after Jo and Zack have dinner with Zack's colleague Margot and one of his law firm's biggest clients, the developer Leland Hunter, Jo and Zack's house is blown up. They're at the lake with daughter Taylor and their dogs, but the house is destroyed. And that is only the first of several terrible incidents. It isn't long before Joanne is witness to events far more distressing than even a destroyed home. She begins to understand what it's like to live in a world where she can count on nothing.