Transcript for Mexico sees record levels of violence this year
And we turn now to an ABC news investigation tonight. We have been reporting here on the increasing violence south of the border in Mexico, several Americans, members of that Mormon family, killed. But tonight, another troubling portrait here. Families in Mexico, parents, mothers, looking for their missing children, but getting no help. ABC's Dan Harris and what he found. Reporter: Mexico is at war. Violence has reached record levels this year. Inside that cooler, we're told there is a hman head. Drug cartels waging open gun battles in the streets. Killing nine Americans just last month. Mothers and children from a Mormon family living there for decades. By conservative estimates, there are 40,000 missing people in Mexico. Lucy Diaz was leading a comfortable life. That all changed one night in June of 2013. I knowhat he was kidnapped, but so far, that's all I know. Reporter: At the time, her 29-year-old son, Luis, was working as a popular deejay in the city of veracruz. Last year, a potentially huge break in the case. The police found Luis's motorcycle and the individual who was riding the stolen bike. Did you bring him in, at least, to interrogate him? And they said, "Not yet." Reporter: And do you think it's laziness? No, I think it's corruption. Reporter: Lucy has now organized hundreds of other mothers who are also desperaly searching for their children here in veracruz. Just ten miles from this dump, over 300 bodies were exhumed at a mass grave. This is a skill you've developed now, to be able to smell for dead bodies? Yeah, yeah. Reporter: But isn't it the job of the police to investigate crimes and find bodies? It is. It is. But this is Mexico. Reporter: Karla quintana is the national commissioner in charge of searching for the disappeared. How have we gotten to the point in this country where it's mothers who have to bear the injury of losing their children and then have to endure the insult of being forced to go then do the searches themselves? Well, I think it's because the government, they don't care much about who has been disappeared. Reporter: So, essentially, in this country, you can kill somebody, bury them in a shallow grave and get away with it? Well, I'm a public servant, but I would have to say yes. That is a stunning acknowledgement tonight. I know you also pressed the Mexican president on this. Reporter: At a live, nationally televised press conference, I asked him, will you help Lucy Diaz, and he said yes, in front of the whole country. Nine months later, tonight, Lucy says she has not received so much as a phone call. This is an overwhelming problem, Dan, thank you.
This transcript has been automatically generated and may not be 100% accurate.