The arrest and conviction rate for crimes in Mexico is estimated at between 1% to 5%, a very low rate indeed. Be that as it may, even that is not an accurate representation of incarceration of cartel members considering that even those who are sent to prison walk right out again becuase of corruption, ineptitude or both.
The proof of this statement is the recent jailbreak in the "Centro de Ejecución y Sanciones" prison, located in Matamoros, Tamaulipas. This last Thursday 40 prisoners left the prison between 4 and 5 AM...not just 1 or 2 prisoners but 40. This is in addition to the escape of 53 prisoners less than a year ago (16th of May 2009) from the Cieneguillas prison in Zacatecas, most of whom were connected to the Zetas and only a few have been caught again (I believe it is less than 5). Not surprisingly, 50+ prison staff are being investigated for complicity.
Monterrey, Nuevo León was the scene of another shoot-out between the cartels and the military. The gunmen were travelling in at least 10 vehicles when the Marines spotted them and tried to stop them, at the end of the battle, 6 of the gangsters had been killed. The mayor of Cerralvo, José Estaban Quintanilla stated that around 11 PM there were 3 different gunfights lasting over a period of 40 minutes that left at least 14 dead (Cerralvo is about 50 from Monterrey). The total for today is now at 2350 with 27 more deaths added yesterday.