When there is research on guns and crime you will extremely rarely find unbiased personalities behind that research. So I want to be honest with you: Personally, I am mostly to be found on the "pro" side of the gun debate. If you find any bias in my research apart from choice of topic, I will take the blame.
An amazingly high correlation between firearms and suicide was found for Austria in the medical literature. That study has fallen prey to the ratio fallacy in its original form as known from Pearson (1896). Using appropriate statistical methods allows to confirm the FSS proxy for gun ownership. It also leads to an intriguing finding concerning substitution between suicide methods, although this finding's significance is wavering, depending on your standards for variance estimation. Read about it here.
For my research on the quantitative analysis of school shootings I needed a random-case-control-study-generator. I have written the reccsim package for R, which allows you to generate a random case control study with binary exogenous variables from some known parameters.
Inspired by Britta Bannenberg's wording "Die seltenen Vorkommnisse verbieten ein quantitativ orientiertes Vorgehen." (quantitative analysis of school shootings is 'prohibited', here, p. 38), I did some researching. Result: With good data it would be very simple and possible to conduct quantitative analysis of shool shootings. Read about it here.