He worked on assignments for several organizations, including EFE and Canal Plus, and was a cameraman for the Telecinco television network for eight years, covering major news stories such as the kidnapping of his coworker Jon Sistiaga in Macedonia, the 1998 Baghdad bombings, the Kosovo War in 1999, various reports from the BIO Hespérides ship in Antarctica in 2001, a report from the French caves of Lascaux, the incident on Perejil Island during the same year, and the Prestige oil spill.

The round hit the 15th floor, where the Reuters team was staying, causing the immediate death of the Ukrainian journalist Taras Protsyuk.

(Tape B, 1:11:45) In August 2003 the US military announced the results of an enquiry into the incident, which concluded that the firing of the shell was legitimate because there was positive evidence they were under observation from attackers.

Following the death of Couso, there were protests in front of the American diplomatic posts in Spain and several civil and judicial actions in order to determine the liability of the people involved.

The Sala II de lo Penal of the Audiencia Nacional closed the investigation on 10 March 2006, saying that the event was an act of war, a decision which was appealed by the family of the deceased before the Tribunal Supremo.

On 5 December 2006 the Supreme Court of Spain (Spanish: Tribunal Supremo) unanimously granted the appeal by Couso's family against the decision by the Audiencia Nacional.

Santiago Pedraz, judge of the Audiencia Nacional, reactivated the international arrest warrant against the 3 military personnel on 16 January 2007, after a protracted battle against the state prosecutor.