Well, the phrase "Australian Twin Sisters shot at Denver Shooting Range" does sound a little odd if it was a suicide.
However, to be fair to Kenny, that is how it was initially reported. See this link from the BBC web site of Wednesday;
http://www.bbc.co.uk/news/world-us-canada-11771852
And compare that to how it's being reported now;
http://www.bbc.co.uk/news/world-us-canada-11793745