The fifth edition of this enduring work features new material on how today's police officers can meet the ethical challenges of policing while living up to heightened demands for better security. Professor Delattre addresses the need for careful selection of law enforcement recruits by using four examples of intellectual competence and moral probity in policing and law enforcement: the investigation of mass murder at Columbine High School, which was conducted under FBI leadership; the effective transformation of the police force in the Rampart Area of Los Angeles following the catastrophic police misconduct of the 1990s and the reforms of the Los Angeles police department as a whole; the successful anti-gang work conducted by the Fairfax County police in Virginia; and the design and progress, since the September 11 terrorist attacks, of the New York State Office of Homeland Security.