In 2002, President Jorge Quiroga signed the Declaration of Chapultepec, promising to support and promote press freedom in the country. The constitution provides for freedom of the press. However, journalists are constrained by strict defamation and slander laws that carry sentences of up to three years' imprisonment. As a result, many journalists practice self-censorship. Journalists must be licensed by the government and must hold a university degree in order to practice their profession. Reporters covering corruption stories have been known to face verbal intimidation by government officials, arbitrary detention by police, and violent assaults. One journalist was murdered this year after a bomb exploded in the back seat of her car, although the motive is unknown. Newspapers are privately owned, and there is a mix of state and privately run radio and television stations. In practice, state advertising revenues often go to newspapers that are favorable to the government.