Manuel Gomez Torres, the 74-year-old mayor of Ayutla, Jalisco, was ambushed by unidentified gunmen as he returned to his ranch Sunday along with his bodyguard, identified as José de Jesús Hernández, 60. Both men died at the scene.
Jalisco Attorney General Carlos Najera, who has taken personal charge of the case, said his initial investigations suggested the murders were probably related to narcotics activity in the municipality, located 70 miles to the southwest of Guadalajara,
Najera admitted there was "a certain reluctance" of the part of many residents of Ayulta to cooperate with the investigation.
The region is considered a stronghold of the Cártel Jalisco Nueva Generación, which is battling the Zetas for drug running rights in the state.
One month ago, the former deputy police chief of Ayutla was gunned to death in a crime that has yet to be resolved.
Najera also revealed that two weeks ago kidnappers returned two Ayulta municipal employees safely to their families after an undisclosed ransom was apparently paid.
Najera said it was "suspicious" that the municipal police force had failed to keep state authorities informed about an increased presence of armed groups in the region in recent weeks.
The current director of Ayutla's police force, Juan Pablo Murguia, had apparently failed an examen de confianza, or confidence control test, that aims to ensure every officer's aptitude and trustworthiness. He nonetheless has continued in his post.
Gomez Torres was a member of the National Action Party (PAN) and, by all accounts, widely respected in Ayutla, one of Jalisco's smallest municipalities with a population of just over 12,000.
Miguel Angel Ibarra Monraz, the PAN leader in the Jalisco Congress, has called on Governor Aristoteles Sandoval to replace Najera. He said his security strategies have been unable to stem to tide of violence in the state since the Institutional Revolutionary Party (PRI) took over the statehouse in 2012.