MEXICO CITY — A man was arrested Monday in the shooting death of a journalist who worked for the newspaper El Heraldo de Chiapas, and authorities were searching for three other people suspected of having ordered the killing.
Luis Alberto Sanchez, a homicide prosecutor in the southern state of Chiapas, said in a video statement posted online that the detained man is believed to have acted as a lookout outside the home of reporter Mario Gomez.
Sanchez said the man allegedly belonged to a local drug gang and identified the gang's leader, his right-hand man and the lieutenant's wife as the purported intellectual authors of the murder.
State and federal police in the town of Yajalon, where Gomez was slain, were under investigation by anti-corruption prosecutors to see if any might be implicated, Sanchez added.
Surveillance camera video captured the moment Friday afternoon when two people rode by Gomez's home on a motorcycle and the one in the rear fired at him. Neighbors went to his aid, but he did not survive. According to Chiapas prosecutors, he was struck by four bullets, and six shell casings were recovered at the scene.
Gomez, who had worked for El Heraldo de Chiapas for nearly a decade, was a general assignment reporter who covered a variety of topics including crime, security and political violence during the recent campaign for Mexico's July 1 nationwide elections.
Two years ago, the media advocacy group Articulo 19 documented that Gomez had received death threats after publishing an investigation linking a congressman and an alternate lawmaker to purported corruption.
Articulo 19 said Gomez was assigned protective measures that were later suspended by the state government "without the reason for the withdrawal being made known."
Mexico is one of the deadliest countries for journalists, with at least 10 slain so far this year and more than 30 killed during the six-year term of President Enrique Pena Nieto, whose term ends Dec. 1.
Jan-Albert Hootson, Mexico representative for the New York-based Committee to Protect Journalists, urged authorities to determine whether Gomez's killing came in retaliation for his work.
"Journalists in Mexico will continue to fall victim to deadly violence when the killings of reporters linger in impunity," Hootson said in a statement.
Over the weekend, Chiapas prosecutors said Gomez's journalistic work was the main line of investigation.
In an editorial, El Heraldo de Chiapas demanded "a thorough investigation to find those responsible."
Chiapas was home to the 1994 uprising by Zapatista rebels, and political violence and conflicts over land are common in the state.
It is currently governed by the Green Party, but is set to come under control of the leftist Morena party of President-elect Andres Manuel Lopez Obrador, after the Greens lost the gubernatorial race two months ago.