Overall violent crime is not much higher in the US versus other developed nations. Various prominent cities in Europe have serious violent crime problems for example, such as London and Amsterdam. The Netherlands has a higher rate of crime than the US does, and their violence is a lot less lethal. The US rate of lethal violence is higher than its peers and the very easy access to guns is the problem:
https://www.vox.com/2015/8/27/9217163/america-guns-europe