A 21-year-old man has been detained in connection with the shooting death of a 15-year-old boy in the Pegaso park in Barcelona. The detained individual is described as the "presunto sicario" or alleged gunman.

This arrest is the second to be made in the case. Further details about the incident and the arrest can be found in El Mundo.

The source provides more information about the case, including the circumstances surrounding the arrest and the investigation. Readers can refer to El Mundo for a more detailed account of the events.