I received a request for help from James in the UK. Here was my response (actually sent in two pieces, but combined here):
I would like to suggest you follow the links in the post Just One Question. The Center for Disease Control (CDC) reviewed a number of studies and was unable to conclude gun control made people safer. That review, and the studies they looked at, are probably the most reliable data points.
The following links are not to statistics. The CDC study would be the best reference I have for that.
I don't have it but I think this book would be very useful:
http://www.joyceleemalcolm.com/books/guns_and_violence
I've read a few excerpts and it seemed quite good.
This might also be worthwhile:
http://www.joyceleemalcolm.com/books/keep_and_bear_arms
For more background and potential ways to approach the problem take a look at these:
http://blog.joehuffman.org/SearchView.aspx?q=%22James%20Kelly%22
http://blog.joehuffman.org/CategoryView,category,PlacesWithoutGuns.aspx
http://www.independent.co.uk/news/uk/this-britain/britain-is-capital-of-crime-says-us-tv-channel-715251.html
http://www.reason.com/news/show/28582.html
Good luck!
Update:
Gun control also violates my Jews in the Attic Test.