(1) The United States is on average much more
violent homicidal than other developed nations. For example, here are the most recently available homicide rate per 100,000 inhabitants for ten countries:
South Korea: 0.6
United State: 4.7
(2) Both the violent crime rate and the homicide rate in the US have declined by about half over the past 25 years. Over the past half century violent crime and homicide in America have followed a roughly parabolic pattern:
(3) The reasons for the massive run-up in the violent crime rate between 1960 and 1990, and (especially) for the equally sharp decline in the rate since then are not well understood. Many theories have been proposed, but none of them are especially well supported. The most that can be said at this time is that both the run-up and the decline each had many causes, but identifying and sorting out the relative importance of those causes is extremely difficult to do.
(4) Mass shootings intended by their perpetrators to draw media attention have a symbolic cultural significance that goes far beyond their minuscule role in overall crime statistics. Among other things, they throw light on the fact that the United States remains, in comparative terms, a remarkably violent place, although it is true that we are now “only” about five times rather than ten times more
violent murderous than our economic peers.
Edited to reflect that the big gap between the US and otherwise similar nations is in regard to homicide, as opposed to violent crime per se.