Canada's judiciary plays an important role in interpreting laws and has the power to strike down laws that violate the Constitution. The Supreme Court of Canada is the highest court and final arbiter and is led by the Right Honourable Madam Chief Justice Beverley McLachlin, P.C. Its nine members are appointed by the Governor General on the advice of the Prime Minister. All judges at the superior and appellate levels are appointed by the Governor General on the advice of the prime minister and minister of justice, after consultation with non-governmental legal bodies. The federal cabinet appoints justices to superior courts at the provincial and territorial levels. Judicial posts at the lower provincial and territorial levels are filled by their respective governments (see Court system of Canada for more detail).
Common law prevails everywhere except in Quebec, where civil law predominates. Criminal law is solely a federal responsibility and is uniform throughout Canada. Law enforcement, including criminal courts, is a provincial responsibility, but in rural areas of all provinces except Ontario and Quebec, policing is contracted to the federal Royal Canadian Mounted Police (RCMP).