Up-to-date verified numbers on gun deaths across the US, listing city, state and news source:
https://www.gunviolencearchive.org/reports/number-of-gun-deaths
Everytown for Gun Safety’s “Mass Shootings in the US:2009-2017” provides details about each shooting:
https://everytownresearch.org/reports/mass-shootings-analysis/
Database of state firearms laws from the Boston School of Public Health:
https://www.statefirearmlaws.org/
Wikipedia’s article on Iowa gun laws is easy to digest:
https://en.wikipedia.org/wiki/Gun_laws_in_the_United_States_by_state#Iowa
An excellent overall central clearinghouse for most topics of interest to gun control advocates is the Schippensburg (PA) University library database:
http://library.ship.edu/c.php?g=21651&p=126898
Here’s a snippet of the firearms industry’s economic impact report in Iowa, from the National Shooting Sports Foundation (NSSF):
http://www3.nssf.org/share/PDF/EconomicImpact/2018data/iowa.pdf
Use this site from Center for Responsive Politics to track the influence of business interests on the politics of gun control and gun rights:
https://www.opensecrets.org/news/issues/guns
Report on gun violence in Iowa from the Center for American Progress:
https://www.americanprogress.org/issues/guns-crime/reports/2018/04/04/448768/gun-violence-iowa/
Iowans for Gun Safety: Download current brochure