Peter, you et al are again moving the goal post, i.e., the subject matter of this thread (and previous ones) - which is mass shootings.
As it was pointed before by John, when we start analyzing one aspect (mass shootings and gun control), you (rhetorical) switch to overall shootings. We start analyzing and breaking down overall shootings, you switch to terrorism, we start about that, you switch to mental issues, and on and on in circles we go.
"And yet..." in spite of much tighter control, mass shootings are happening in Europe at the same or higher rate than in the States, regardless of causes and modalities. In other words, tighter gun control, which is advocated ad nauseum here and elsewhere is NOT the answer.