Often, the conversation around gun violence becomes a conversation around political identities and ideologies rather than one about truth and how we arrive at it. This website is interesting in that it focuses on what we know through science. It uses appropriate, often cautious, language to come to its conclusions. The site is worth exploring. The table below summarizes the meta analysis of existing research done by the Rand Corporation. Click through the image to find the appropriate page. You can click in the table to see what research and evidence there is to support conclusions about efficacy.
Here is a link to the main page. Worth exploring for those curious about gun policy but also as an interesting case study on the use of the scientific method to help us understand and evaluate a problem in society.
https://www.rand.org/pubs/research_reports/RR2088.html