The circumstances that led police to openfire remain unclear, but reports from eyewitnesses suggest the shooting took place after a group of demonstrators rushed at a line of police officers.
At night, by the light of a fire out in the open, Pereda whiled away the time recounting adventures that had taken place exclusively in his imagination.
The attackers drove up to the party, taking place in the open but within the grounds of a recreation centre, before opening fire on those present with a machine-gun, reports said.