I am so sorry. Back in February I wrote about the sharp fall of the homicide rate in the state of Rio de Janeiro. Daniel Cerqueira, an IPEA economist , has just found out that the data is seriously flawed (in Portuguese). Check Graph 4.2. From 2006 on, there was a huge increase of violent deaths with "unknown causes" and the victims have demographic profiles strangely similar to the victims of homicides. True, homicide rates have fallen, but it was not as sharp as the official data shows.