About 2,500 people marched through the western city of Fribourg on Sunday in memory of a teenage girl who was murdered earlier this month.
The parents of 16 year-old Lucie Trezzini, who led the silent demonstration, spoke briefly to the crowd, calling for the introduction of an abduction alert scheme.
Her father said it was impossible to know whether such a scheme could have saved Lucie, but that everything must be done to avoid similar tragedies in future. His daughter would then not have died in vain.
Her mother said there was no idea of revenge in the demonstration, but that the positive forces that had been evident since the murder should help to lead to decisive action.
Trezzini, who was working in central Switzerland as an au pair, was killed by a 25 year-old man who lured her to his flat by telling her he was looking for girls to model jewelry.
The man, who had a history of violence, has confessed to the killing.