While I disagree with marking this answer as "spam or rude or abusive", I'd agree that it was rather a low quality answer thus some downvoting was fully justified. Moreover, as the subject and explaining factor is quite contentious, in such cases even better sourced explanation may still risking being a downvote magnet.
Not to be overtly general:
- First link tangentially mentions issue of IQ and crime. Even if it was emotionally neutral issue like fruit flies or pea plants, you even did not bother to support it by data on what IQ is measured for different ethnic groups. Not good enough to prove your point and you already enter on collision course with people who maybe generally agree with evolution, but consider our specie intellectual capabilities to be exempt from it in last 70k years or disagree with the concept of IQ as a whole. You could have simply used Latino crime rate from the US, and extrapolate that for rest of South America.
- Urbanisation rate - yes they have slightly higher rate than other continents, so by default would have more violence in cities, because of simply having more population there.
Both of those factors, I'd mark as possible contributors. However, it seems that you missed elephant in the room, what wrongly or correctly, some people interpreted very emotionally - some of those countries could be marked as failed states. Even if you implicitly go in to ethnic differences (genetic or culture factor) as the causal factor for observed quality of institution, then such mechanism would require extra explanation as it clearly does not work in for example Eastern Europe.