Switzerland is very different to the US concerning guns in most ways (including the fact that it only has around 1/4 of the guns the US has, per capita).
This article from the same website you linked is quite informative in my opinion:
https://www.swissinfo.ch/eng/business/florida-school-shootin...
[0]: https://www.swissinfo.ch/eng/homicide-report_statistics-show...
[1]: https://en.wikipedia.org/wiki/Crime_in_Switzerland#Crime_sta...