Description Detective Chief Inspector John Luther, portrayed by Idris Elba, works for the Metropolitan Police Service, in the Serious Crime Unit. He is a legendary figure on the force both for his dedication and his ingenious approaches to solving cases. However, the horrors of Luther's job have given rise to emotional demons which often put him at odds with colleagues and loved ones. Because of this, he constantly breaches protocol and uses unorthodox (and sometimes illegal) methods, such as breaking into properties without warrants to find clues or violently threatening suspects or witnesses. He is also given to belligerent fits of anger. Nevertheless, he is known to hate firearms, and he refuses to kill or directly cause the death of suspects.