You just quoted two rightists. Lula, is living in a country were gun violence is not only his problem.
As for leftist activists, you should know that they are being stabbed and killed all over the world in complete silence of the mainstream medias.
If I, for example, were to be stabbed by someone one day for a political reason. Absolutely NO mainstream media in France would even report my death in its contextual importance.. At best you would get a "there was a murder here, the police is investigating" end of story.