Carlos Manuel Patiño Casanova was parking his car on a street in Rentería with two co-workers, Esteban Fariña and Francisco Rosco, when an ETA member fired a number shots at the car tyres. Eye witnesses reported that the gunman looked no older than 20. He got out of a Renault 12 holding a machine-gun and opened fire on the men from close range. The other two occupants of the car fired from inside the car, using another machine-gun and a pistol.
ETA believed the three victims to be members of the Civil Guard, although none of them had any links with the force. Esteban Fariño and Francisco Rosco were wounded, but survived.