The first link below is to a data-rich report he recently updated entitled "America's gun problem, explained." Very informative. The graphs, charts, and embedded videos alone are worth it.
The second link is to an Aug. 5 podcast interview with Lopez, in which he reminds listeners of the NRA's aggressive pro-gun agenda since the 1970s that has majorly contributed to America's gun culture.
"America’s gun problem, explained"
https://www.vox.com/2015/10/3/9444417/gun-violence-mass-shootings-us-america
"A Green New Deal, but for guns" – podcast interview with Lopez
https://art19.com/shows/today-explained/episodes/4164d3b0-0624-49f9-b8fe-bfdff3eec286