Not that we already know this is done but here's a good explanation of how statistics are falsified and misrepresented in one instance.
https://bearingarms.com/tom-k/2018/08/06/understanding-claim-1259-murders-concealed-carry-permit-holders/
https://bearingarms.com/tom-k/2018/08/06/understanding-claim-1259-murders-concealed-carry-permit-holders/