Santa Fe Police Chief Kevin Kerney travels to a California ranch looking to buy some prime quarter horse breeding stock. Instead, he finds himself the prime suspect in a possible homicide when a guest at the ranch, Clifford Spalding, is found dead. Confronted by a determined cop unwilling to let him off the hook, Kerney decides to conduct his own investigation. As he digs into the victim's background, he learns that Spalding's ex-wife refuses to believe that her son, a soldier killed in Vietnam some thirty years ago, is dead.

Kerney digs deeper and soon finds himself sharing the woman's doubts: Did Spalding's current wife, a much younger woman, orchestrate his murder with the help of a lover? Did a California cop collude with Spalding to keep his ex-wife from learning the truth about her son?

Slow Kill races from West Coast to East Coast as Kerney attempts to find the answers to a thirty-year-old mystery and extricate himself from a situation that could ruin his career.