Well, looking just at murder rates, here are the 1991 figures:
Murder rate (per 100,000 people, 1991 figures):
United States 8.40
Canada 5.45=20
Denmark 5.17
Germany 4.20
Norway 1.99
United Kingdom 1.97=20
Sweden 1.73
Japan 1.20
Finland 0.70
Source can be found
hereThe US had in 2000 the lowest murder rates in over 30 years - at 7.02 per 100,000 people. For Scandinavia the average is (5.17+1.99+1.73+0.70)/4 = 2.4, which is significantly lower than the US stats even for today. Danish murder rate has since '91 declined and is more in line with the other Scandinavian countries.
Perhaps more telling is the following figure:

Source can be found
hereMy claim was that the US had more violent crimes or more specifically more serial murderers and impulse murders or more murders in general. I was implying that it was a more violent society - despite having the death penalty as a 'deterrent', whereas Scandinavian countries don't.
Anyway, on that table it is quite clearly visible (using the 1993 figures): US had 443 serious assauts per 100,000 people, a country like Denmark had 179. The US in other words having nearly 250% more serious assaults. Looking at murder figures:
US at 9.5 in 93, Denmark at 4.8. Even using the lowest-in-30-years 2000 figure, there's still a substantial difference.
What the figures don't show are what I call the Psycho killers and Stranger Killers. Psycho killers being serial murderers, of which this countriy hasn't seen many at all. We had a mass murderer here - a Danish national that killed his mother while in the US and then killed a potato and her two children before chopping them up and disposing of the bodies. Anyway, I've gone through those death row records and see that there are lots of people there for either killing multiple people or for raping and then killing women. This is uncommon here when compared to the US. Stranger killers is to me people who murder someone they haven't met before - a la killng after a rape, or in road rage or the like, although whether that is manslaughter or murder would depend on the DA, so never mind that.
I guess I should dig some to see if I can get comparative numbers in this regard. And as I said, I'll spare my comments on the matter until I've seen others, in order to not taint the discussion too much. I suspect however that one part of the explanation that will be put forth will be the 'race issue', as there are some works out there on that, including one made in Whitney which has been proven utterly false, but if you got other sources, post 'em.
Martlet, if you need more references or the like, ask and I'll dig some more. Just sorta in a hurry right now, so will do it a bit later if necessary.