Mexico City, September 14 (teleSUR-RHC)-- The attorney general’s office of Mexico City announced on Sunday that Cesar Omar Martinez Zendejas, the third suspect in the murder of photojournalist Ruben Espinosa, activist Nadia Vera and four other women, had been imprisoned.

The man was captured on Friday.  Martinez Zendejas is believed to be linked to the drug cartel Los Zetas, and has been singled out as the murderer of Colombian citizen Mile Virginia Martin, one of the women that was tortured and killed with Espinosa.  He allegedly wanted to rob her a shipment of cocaine.  Mexican authorities said they identified the man based on his voice, his mobile phone and different evidence found at the crime scene.

The man was also captured in CCTV footage, being the last of the three suspects to leave the scene.  However, according to official reports, it is still not clear what would be the connection between Martinez Zendejas, the victims and the Zetas drug cartel.

One of the women killed with Espinosa and Vera, another of the victims was a make-up artist and another one was the maid of the house, which is why investigators believe the motive behind the murders could be traced to the Colombian citizen, who was allegedly a model.

However, critics have dismissed this allegation claiming it was widely known that Espinosa had been repeatedly threatened by local authorities, including the governor himself, while living in Veracruz.

Espinosa, who worked for the critical magazine Proceso, and the other four victims were tortured and murdered in July in an apartment in Mexico City.

He and Vera fled Veracruz to Mexico City fearing for their lives after months of threats.

Authorities had previously captured two other men who entered the apartment together with Martinez Zendejas, all caught on video footage, one of them a former police man.

So far, investigations have confirmed that one of the suspects, former policeman Abraham Torres Tranquilino was an acquaintance of Martin, and he entered the building after she opened the door to him under a false pretext.

The capture of Martinez Zendejas could shed new light to investigators, which have advanced little in over a month since the murders took place.