Christchurch crime writer Mark McGinn cashes in on his many years observing lawers and judges in action, in his fourth novel, Presumed Guilty. It's the latest in a series about the personal and professional life of Q.C.Stasha Stace. In Presumed Guilty, the editor of an investigative magazine is charged with murdering his journalist wife. His ex, Stasha, is persuaded to defend him. Lynn Freeman talks to Mark McGinn about what a high-flying lawyer brings to the crime novel genre. Presumed Guilty by Mark McGinn is out on the Merlot Publishing label.