Who you task with collecting, retaining, and disseminating certain data defines what data is collected and how, which later informs its use. Since if it's collected, it will be used. And even if it's not collected, if you collect enough other data, it will be inferred, and then used. Which is why I bring up algorithmic policing.
Injuries and deaths involving firearms as a tool are, in large part, criminal acts. Homicide is not legal barring affirmative defense, suicide is not legal, itself being the fatal expression of an underlying disease(likely) or crime. Legal possession of a firearm is indeed something else all together. Accidental deaths, I'll have to think about. How to treat specific forms of injuries, I'll probably give you. How to address crimes, tangentially touched, no.