That's a really surprising example. Paris has nearly identical crime level to San Francisco.
From personal experience, I did not feel particularly safe in Paris when visiting (compared to e.g. Berlin).
Moreover, Paris has several neighborhoods and suburbs that are very unsafe and most people avoid going there. One could say Tenderloin in SF has a similar reputation, but it's very small and easy to avoid.
I think OP was referring to shootings. In France, as in most of Europe, it's not trivial to get access to guns. So the risk of getting shot in Paris is small, but of course you still might get stabbed.
I was talking only about shootings. But if we are comparing anecdotes regarding your example I happened to also live in one of these unsafe suburbs, and visiting LA, SF or Chicago and getting in the wrong neighborhood seemed order of magnitude less safe. Gangs are not armed, you don’t hear gunshots at night or people screaming in the city center, and you don’t encounter aggressive drug addicts. All of this never happened to me in decades in Paris but did in one trip to the these US cities.