Mexico City (CNN) -- On the eve of a meeting of Mexico´s top prosecutors and judicial officials in Veracruz state, authorities Wednesday were still trying to determine who left 35 bodies in a busy thoroughfare there -- and why.
Investigators said a video may hold clues to how unidentified men managed to drive two open-back trucks filled with corpses through rush-hour traffic and then abandon them, blocking traffic as stunned onlookers watched.
Police in the Gulf coast state of Veracruz found the abandoned trucks and the bodies near a shopping mall in the municipality of Boca del Rio on Tuesday. Mexico´s state prosecutors and court presidents are scheduled to meet there Thursday.
Photos of the scene showed the two trucks with their back gates open, the bodies falling out onto the street. People on a nearby overpass looked down on shirtless bodies piled on top of each other.
¨This is a way of making yourself known, and saying, ´We have the power, we can do this with impunity,´¨ said Jose Reveles, a security analyst. "'We do it at five in the evening, in a heavily traveled avenue. We drive two trucks loaded with cadavers, and nobody stops us.'"
Drug-related violence has been on the rise in Veracruz as cartel members battle over territory.
But the large toll gripped headlines across Mexico and drew attention from peace activists gathering in a conference in the nation´s capital Wednesday.
"They were left like trash in the street," said Edgardo Buscaglia, president of the Institute of Citizen Action for Justice and Democracy.
Buscaglia, an expert on organized crime, told audience members that the bodies found in Veracruz are a reminder that Mexicans must not become desensitized to violence, even if authorities say the victims had criminal histories.
"The value of a human life does not decrease because it has a criminal background or not," he said.
The dead included 12 women and 23 men.
The video may show that the two trucks were guarded by other cars that could have doubled as getaway vehicles, Veracruz Attorney General Reynaldo Escobar Perez said Wednesday in a radio interview. He did not say where the video came from.
Investigators also are looking into whether police colluded with the people who discarded the bodies, he told W Radio.
As of Wednesday, morning, 95% of the bodies had been identified through databases, Escobar Perez said.
Most of them had criminal records, he said. One of them was identified as a local policeman who disappeared about 15 days ago, he said.
In another interview, the attorney general said that the victims died of suffocation. Only one had a bullet wound, he said. The state of the bodies led investigators to deduce they died shortly before being abandoned, Escobar Perez said.
The attorney general on Tuesday described the grisly discovery as "unprecedented."
"It hasn't happened before in the state of Veracruz," he said.
The two trucks were abandoned in the middle of the highway, witnesses said. Their gates were open and bodies had fallen out.
Hours later, bloodstains remained on the road as troops stood guard.
Boca del Rio is in Veracruz state's most populated area. It has become a frequent site of clashes between armed groups as drug-related violence grows.
Earlier Tuesday, 32 inmates escaped from three prisons in Veracruz, authorities said. At least 14 of them have been apprehended.
Escobar Perez said none of the bodies that had been identified by Tuesday night appeared connected with the prison breaks.
Government figures indicate that more than 34,600 people have been killed in drug-related violence since Mexican President Felipe Calderon began a crackdown on cartels in December 2006. Other reports estimate that more than 40,000 have died. The latest government figures were released in January.
Speaking at the United Nations General Assembly Wednesday, Calderon decried the violence caused by drug trafficking and called on fellow leaders to put a stop to the burgeoning weapons trade and rampant drug consumption fueling it.
¨Today we must be aware that organized crime today is killing more people and more youth than all the dictatorial regimes combined at this time,¨ he said.
CNN´s Rey Rodriguez, Mario Gonzalez and Catherine E. Shoichet and CNNMexico.com contributed to this report.