The family had been staying at a campsite in Saint-Jorioz with their two daughters. Police say there are still no clues as to the motive for the killings and no arrests have yet been made.
Maillaud said 15 cartridges were found around the car, suggesting all the gunshots had come from outside the car, and an automatic pistol appeared to have been used but no weapon has been found.
He described the discovery as being like a scene from a film: "We don't know who could have done this. We have no idea."