Worth noting a couple of points made in an article in Telegraph (which is of a similar political view to the Mail) that covers the same ground:
"Researchers admit that comparisons of crime data between countries must be viewed with caution because of differing criminal justice systems and how crimes are reported and measured."
"A Home Office spokesperson said: “These figures are misleading. Levels of police recorded crime statistics from different countries are simply not comparable since they are affected by many factors, for example the recording of violent crime in other countries may not include behaviour that we would categorise as violent crime. "
http://www.telegraph.co.uk/news/uknews/law-and-order/5712573...
NB I'm not denying that the UK probably has more violent crime than the US (although I suspect that, just as with gun crime in the US, this is highly concentrated in particular areas and times).