Manríquez had been part of the country's witness protection program, and had received threats as recently as November, according to Mexican publication Capital.
34 year-old Manríquez was director of Radio Kashara, a community station in Santa Rosalía, and was found among vegetation on the side of a road with several stab wounds to his chest. He had three packages of cannabis on his person.
Mexican Daily News reports that he had been harassed after publishing negative commets about the Mayor of Mullerg, Felipe Prado Bautista. Manríquez had also said he had learned from a city official that someone was planning to kill him.
He had previously, in 2016, been the target of the federal witness protection program in the United States.
Manríquez' family reported him missing Sunday afternoon, after he went out for a walk Saturday night and never returned. He was the first Mexican journalist to be killed in 2019.
According to the Mexican National Human Rights Commission, approximately 140 journalists have been killed in Mexico since 2000. Since 2005, the whereabouts of 21 media workers remain unknown.