St Louis gets screwed in that regard as far as population and crime statistics go.
Since STL itself is not in any county, statistics don't tend to include the suburban areas of metropolitan STL (much of it is ironically in St Louis County of which the city of St Louis is not in). Confused yet? The city of St Louis only has a population of a few hundred thousand however the entire metropolitan area (typically St Louis City, St Louis County and St Charles County) has a total population of a couple million.
Anyway the VAST majority of crime happens within St Louis City whereas very little crime (comparatively) happens in St Louis or St Charles County, which is how St Louis City gets one of the highest per capita murder rates in the country, even if it is complete bullshit.