Randy points us to this article in The Economist. The article does a great job explaining succinctly why A) there appears to be so much violence in Rio, and B) why it's in the favelas, and not a city-wide event:
"A further reason for Rio’s spectacular violence is that it has three large, competing drug factions, whereas in other big cities (including the largest, São Paulo) one gang is dominant. A recent study from Rio de Janeiro state’s government on the economics of the local drug business suggests that, because of this competition, far from living like characters in an MTV hip-hop video, Rio’s dealers are operating at “close to break-even”.
Using a conservative estimate for total annual drugs sales in the city, of R$316m ($182m), the study reckons that after buying the product from wholesalers, employing a sales force and investing in capital (guns, mainly), Rio’s dealers make combined annual profits of R$27m ($15m). The wage structure within the factions appears to be surprisingly flat, far more so than in the American gang analysed in 2000 by two academics, Steven Levitt and Sudhir Venkatesh. Rio’s dealers seem to be an exception to Brazil’s national picture of unequal income distribution."
It's a quick run-down, and does a good job distributing the blame. While many uninformed non-Brazilians, many racist/classist (no matter how much they deny it) Brazilians, and foreign media reports place the blame solely on the drug gangs (and the favelados more generally), the economist reminds us that there's a long legacy miscues (to put it euphemistically) from other groups as well, including governmental policy-making:
Past mistakes include making accommodations with drug-dealing factions in the hope of keeping them peaceful. Rio’s police force is also part of the problem. Some of the weapons used by drug dealers are sold to them by the police, and officers still execute too many people on the spot rather than bother with prosecuting suspects, making favela-dwellers regard them as no more a source of justice than the drugs gangs.
The article also mentions the existence of militias in the favelas and around them, though it doesn't mention that these militias are often composed of former and current members of the police. Nonetheless, the (brief) article is the first I've seen in the foreign press that really understands the complexities of the violence and drug economy in Brazil. These complexities are why last week's violence was not initially an attack on police forces in Rio (as many headlines and reports tacitly or explictly framed it), and are why the Olympics are not in any grave danger from these types of incidents. And if the media, both in Brazil and abroad, would take better care to understand and report on these complexities, then maybe bringing an end to the violence could be a more realistic possibility than it is when media reports simply frame the city as a place of extreme violence and treats all the urban poor and favelados as criminals. Maybe then, images like the one above will become more uncommon.