Mexico is seeking the extradition from the United States of the son of a Sinaloa cartel drug lord over the 2017 murder of acclaimed journalist Javier Valdez, the attorney general's office said Thursday.

Damaso Lopez Serrano, the son of former top "El Chapo" lieutenant Damaso Lopez Nunez "El Licenciado", is accused of being the mastermind behind the killing of Valdez.

An arrest warrant for Lopez Serrano was approved Thursday afternoon after prosecutors interviewed members of the Sinaloa cartel who testified against him, the attorney general's office said in a statement.

Valdez was gunned down on May 15, 2017 in Culiacan outside the offices of the Riodoce weekly, which he co-founded in 2003 and was dedicated to reporting on organized crime and corruption in Sinaloa.

Members of the Sinaloa cartel have been implicated in the killing.

Valdez, a respected crime reporter and expert on Mexico's multi-billion-dollar drug trafficking industry, published an article shortly before his death in which Lopez Serrano was referred to as "Sir Nobody."

Javier Valdez, a noted expert on Mexican drug cartels, was gunned down on May 15, 2017 in broad daylight outside the offices of his newspaper
Javier Valdez, a noted expert on Mexican drug cartels, was gunned down on May 15, 2017 in broad daylight outside the offices of his newspaper AFP / HECTOR GUERRERO

Lopez Serrano turned himself into the US Drug Enforcement Administration in July 2017 and, together with his father, has been cooperating with US authorities in exchange for reduced sentences.

Known as "El Mini Lic," Lopez Serrano was a godson of former drug kingpin Joaquin "El Chapo" Guzman, who is serving a life sentence in the United States.

El Chapo's arrest in January 2016 triggered a war for control of the Sinaloa cartel, pitting two of his sons against another faction led by Lopez Nunez.

Lopez Nunez -- a former prison director who once helped El Chapo escape from jail, then teamed up with him -- was himself arrested in Mexico City in May 2017 and extradited to the US the following year on drug charges.

Valdez, who was 50 when he was killed, was a winner of the prestigious International Press Freedom Award and a longtime contributor to Agence France-Presse.

Reporters Without Borders, which regularly ranks Mexico alongside war-torn Syria and Afghanistan as the world's most dangerous countries for news media, said 10 journalists were killed in Mexico in 2019.

Violence linked to drug trafficking and political corruption is rampant, and many murders go unpunished.

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