these are some of the first graves discovered outside of igwala.those who live nearby say the drug gangs have used this property for years to dump bodies. >> reporter: i asked a federal policeman on duty if he had heard the same stories. that this had always been a place where cartels bury their victims. >> reporter: now, police won't let us go any further, beyond this point. but some of the graves found here outside of igwala are about two kilometers up this road. and locals tell us at any time day or night for years, they would see cars go up the hill, quite full, and when they came down, they would be pretty much empty. this man has lived here for decades, he sleeps on a dirt floor. he would rather do so than be part of the gangs. >> reporter: many with few prospects do take the offer. but he couldn't be one of them. three of his 97 fuse have been missing for years. he often writes poetry to deal with the pain amidst so much death. his latest poems are honoring the missing 43 students. >> reporter: the fate of the students is still unknown. thei

>> already the mayor of igwala fled and was eventually captured. the governor of the state of guerrero where these incidents occurred stepped down and now calls across the country are trying to seek the downfall of president pena nieto. i don't think the president is going to step down any time soon over this incident. it's difficult to establish a direct link of responsibility there but i do think that the president is going to have to respond very boldly to the demands of the public protestors. some of whom are wielding molotov cocktails. so the federal government is very concerned. they have already announced, the president has already announced he is going to redouble efforts to promote judicial sector reform in mexico, speeding up the time line for implementation of a new criminal justice system. also he is going to i think in the coming days going to announce a new law enforcement reform, police reform that may centralize policing to create one common command structure for all police in mexico which may or may not have the intended effect of

so that for example, in the concrete case of igwala and the 43 students, what we know is that the mrs. mayor for lack of a better word, the wife of the mayor, was the sister of three gang members of the united warriors, of the guerreros unidos. they would deposit money to her every month which she in turn fueled into the payroll of the police. so that the police knew who they were getting paid by. they were getting paid by and were answerable to the guerreros unidos. it was veriest for th very he fo say, deal with this, and it was a favor or a service for drug gang. corruption is in every part of the country. people routinely pay a small bribe to a cop who stops you on the street. and then i'm sure many, many mayors throughout mexico have to come to sort of some sort of arrangement with the drug groups because if they don't, then they're under threat. any number of candidates, have been killed and many number of mayors. >> there's mass corruption. i want to talk about the change here. how did pena nieto change the strategy on its war on is violence, mr. wilson? >> the prior a very fro