Express kidnappings rose 62.5 percent in 2011 in Rio de Janeiro state, Brazil, according to recently released government statistics. But one research organization has implied there may be reason to doubt the reliability of the government's numbers.

A report by the State Secretariat of Public Security said there were 143 express kidnapping cases in 2011, up from 88 in 2010.

Extortion, overall, rose 37.2 percent. Embezzlement increased by 21.6 percent.

Despite these increases, other crime trends appear to have dropped significantly. Homicide fell 10 percent. Carjacking and muggings both dropped.

Express kidnappings, described by a State Department fact sheet as "quicknappings," are robberies in which victims are forced, often at gunpoint, to extract as much money as they can from ATMs, and then released.

InSight Crime Analysis

Overall, the Rio numbers paint a mixed picture of public security. Despite the sharp rise in quicknappings, for instance, official homicide statistics have been significantly decreasing.

However, according to a study by government research organization the Institute of Applied Economic Research (IPEA), the Secretariat of Public Security may be using distorted data when it comes to measuring homicide statistics. This calls the validity of the other crime statistics into question.

A representative of the IPEA, economist Daniel Cerqueira, has argued that Rio de Janeiro authorities manipulated data in order to make it appear as though homicide rates were falling. Cerqueira told Terra Magazine that since Governor Sergio Cabral took office in 2007, more deaths are being classified as deaths by unknown causes, even though most of them are clearly violent. As such, the steady decline in Rio's homicide rates since 2007 could be the result of fudged numbers.

Cerqueira's argument calls into question just how Brazil authorities are classifying and measuring crime trends. Rio de Janeiro officials may be especially eager to highlight progress in public security as·the 2016 Olympic Games approach.