The Mexican state of Jalisco has been forced to suspend a purge of dirty police after criminal groups posted recruitment ads targeting fired officers, highlighting a serious problem for the nation’s efforts to clean up its police.

As El Occidental reported, an unidentified criminal group posted an advertisement on the Internet targeting the hundreds of Jalisco police officers who have failed the vetting tests. Kicking off with the punchy intro “Have you been fired?” and mimicking the recruiting tactics of a legitimate firm, the ad, which was later pulled, promised benefits and training for officers who went to work for the gang.

Roughly 900 police, out of a total of nearly 24,000, failed Jalisco’s vetting program, which monitors officers’ assets and applies drug tests. However, because of concerns that criminals’ attempts to recruit the fired police could lead to a rash of new gunmen operating around the state, the process of firing the officers deemed unfit for duty has been postponed.

Many have criticized the slow pace of police reform in Mexico, with some 30,000 officers fired nationwide in similar purges. But cases like that of Jalisco demonstrate the inevitable complications that arise when local authorities try to replace hundreds, if not thousands, of active officers, corrupt though they may be. As InSight Crime noted in October, purges in violence-addled Nuevo Leon have left much of the state with a dangerous shortfall of police.

These examples demonstrate that, while police reform is certainly a good thing in the long term, in the short term it can actually play into the hands of illicit actors — both transnational drug traffickers and local petty criminals. Even when the transition does not provide obvious opportunities to criminal groups, they are still capable of slowing the pace of reform; El Universal reported in 2010 that the violence in Chihuahua, which was one of the first states to embrace the oral trial system, forced the government to delay the implementation of several reform measures.

While the problems have grown more apparent with the Calderon administration’s emphasis on vetting police, examples of officers going to work for the criminal groups that they are meant to police have existed for generations. Indeed, Miguel Angel Felix Gallardo, the legendary 1980s capo who set up the federation from which emerged the Tijuana, Juarez, and Sinaloa Cartels, was once a Sinaloa police officer. One of Felix Gallardo’s most notorious criminal heirs, Juan Jose Esparragoza, also made his first inroads into Mexico’s underworld while serving as a police officer.

While Mexico’s armed forces enjoy a cleaner reputation than the police, corruption and desertion are major problems there too. As InSight Crime has reported, recent investigations into three retired generals are an alarming demonstration of illicit activity at the highest levels of the military. In the late 1990s, the defection of a few dozen special forces troops served as the foundation of the Zetas.

Beyond those notorious examples, thousands of lower-level troops desert from the army every year, and many of them wind up in the employ of criminal organizations. Indeed, on at least one occasion, the Zetas employed the same sort of aggressive recruiting tactics as the gang in Jalisco, hanging banners in Tamaulipas border cities in 2008 promising good salaries to any soldiers willing to change sides.

Jalisco, which is the second largest state in Mexico and home to its second largest city, Guadalajara, has suffered a years-long decline in security, as several gangs struggle for control of the region. For most of the 21st century, Jalisco has witnessed somewhere between 375 and 490 murders annually. However, in 2009 that figure jumped to 570, the highest number that decade. The following year, 882 people were murdered in Jalisco, which, according to the National Public Security System, was the highest figure on record. The murder rate has continued to climb; 1,222 people were killed last year, and, so far, 2012 is on a pace to come close to last year’s record high.

The Sinaloa Cartel traditionally had the strongest presence in Jalisco, but the 2010 death of local boss Ignacio Coronel has encouraged the entry of rivals like the Zetas and the Beltran Leyva Organization, as well as the emergence of new gangs like the Resistance and the Jalisco Cartel – New Generation (CJNG). The existence of several different gangs, held together by tenuous and easily broken alliances, is a major driver of the violence. In this respect Jalisco is highly representative of Mexico’s broader security challenges.

Image, above, shows a mayor’s office in Jalisco state which was attacked by an armed group in May.