Pardon my reading comprehension problems, but I don't see that in the referenced article. I see a reference to the "proportion of armed robberies involving firearms has declined", but not that violent crimes has an overall trend down.
Mostly I was trying to address the blanket "the second Australia did [remove easy access to guns], violent crime statistics went up" idea that there is a strong causal connection between lack of easy access to guns and increased violent crime. Snopes rightly said "it ain't that clear" and that statements of that nature are intellectually dishonest. One should be clear about what one is stating, and when using statistics one should have an understanding about what expected variations (for example is 12.8% actually a "marked increase" or just noise?) are likely.
Drawing any strong conclusions between the US and Australia, which have vastly different demographics and cultures, is not an easy task. The US murder rate is about eight times that of Australia, and scores about 10 points worse on crime rates and safety scores that Australia. Australia also has less than 7.5% of the USA population, so the statistics are going to be a lot noisier for the smaller population. Then again, the variation in the USA from state-to-state and region-to-region are quite large making country-wide comparisons less valid in the first place.