One thing I notice whenever one of these shootings happen: no one ever seems to ask questions about what prescription drugs the shooter had ever used. Maybe in most cases the answer is none, but we’ll never know, because no one digs into it. However, since some drugs are known to cause mental side effects (either when you take them, or when you stop taking them), seems like it might be a relevant data point to consider. (I note that this study doesn’t look into this, either.)