In the wake of the murder of Ronan Kerr, a Catholic police officer in Omagh, Laurie talks to Dr Mary Gethins about her research into the Catholic police officers who have joined the Police Service of Northern Ireland (PSNI). She conducted a survey of 300 serving officers followed by in depth interviews with 70 current, trainee and officers and explored the rewards for doing a job which can isolate people from their communities, expose them to prejudice from colleagues and always carries the risk of violence from dissident republicans. Community policing is an enduring problem for the force with some Catholic communities utterly rejecting the legitimacy of the police. Will the PSNI eventually becoming an integrated force, respected by Catholics and Protestants alike? Perhaps the strong reaction against the murder of Ronan Kerr will help establish the authority of the police force across Northern Irish society.Also on Thinking Allowed, Facebook in Trinidad. Laurie talks to Danny Miller about his ethnographic study of Facebook users in the Caribbean island. He finds it can wreck your marriage, put your job in jeopardy but actually bolsters community and augments many of the positive aspects of modern life. Producer: Charlie Taylor.