http://www.aic.gov.au/publications/current%20series/tandi/261-280/tandi269/view%20paper.html
here are some numbers FYI
Thanks for the Stats Fred.
BTW, this is unrelated but poses several interesting questions. The 2nd man trend in mass shootings is clearly established.Is it just a “social” phenomenon?
http://www.sott.net/article/254774-Connecticut-massacre-two-shooters-Look-to-Aurora-Colorado