Forensic experts in Mexico are once again combing a site for clues to the disappearance of 43 students last month.
But by the end of the day Tuesday, the result was the same as it has been for four weeks: no sign of life or death for the teacher trainees, who disappeared from the nearby town of Iguala, in the state of Guerrero.
There are suspicions of human remains at the newest possible mass grave location in Cocula but no proof.
Mexico's Attorney General Jesus Murillo Karam said at a news conference on Tuesday that it was too early to call the newest site a "mass grave" and that experts are processing the scene.
“We have statements that the groups that detained the students [then] gathered in that location, and that diverse actions were taken. We can't do anything until we have clear and complete evidence of what happened there," Murillo Karam told reporters.
This week marked one month since the students went missing on September 26-27 after they clashed with police under mysterious circumstances.
Guerrero's new interim governor took a hopeful tone on Tuesday, offering to negotiate with "whomever is holding our 43 young [men]."
"No one is above the law," added Rogelio Ortega, who was appointed to the position on Sunday after his predecessor resigned.
There has been speculation of a massacre, and nearly 60 police officers and gang members have been arrested in the case.
Authorities allege Iguala's fugitive mayor, Jose Luis Abarca, ordered the attack to prevent the students from disturbing an event held by his wife.