Sacrificial Lam by Gary Guinn

When English professor Lam Corso receives a death threat at work, he laughs it off. When his home is broken into and his wife’s business vandalized, he denies there is any connection. But when the violence escalates, he is forced to face the truth. His wife—a passionate anti-gun crusader—is outraged when Lam brings a gun into the house for protection. The police can't find any leads. Left to their own devices, Lam and Susan are forced to examine their marriage and their values in the face of a carefully targeted attack from an assailant spurred into action by his own agenda.
What will it cost to survive?