New lines of investigation 8 years into the Ayotzinapa case 5:12 (CNN Spanish) — Omar Gómez Trejo resigned as head of the Special Investigation and Litigation Unit for the Ayotzinapa case belonging to the Attorney General’s Office, he announced during his conference President Andrés Manuel López Obrador morning. The president admitted that there were differences because Gómez Trejo did not agree with the procedures that were followed to approve the arrest warrants, and added that the prosecution will appoint another prosecutor. López Obrador also asked the parents of the 43 Ayotzinapa students who disappeared in September 2014 in Iguala, Guerrero, to trust him, since the federal government will continue with the investigation. López Obrador asked the parents to believe him when he says that he receives pressure from many quarters and that he is determined to do justice. Over the weekend, national and international media revealed that 21 of the 83 arrest warrants that are in progress in relation to the Ayotzinapa case were cancelled; 16 of them would correspond to military. CNN sought the Prosecutor’s Office to confirm the information; however, no response has been received so far. Gómez Trejo’s resignation occurs after a controversy that arose after the leak of part of the report of the Truth Commission that had been reserved. Alejandro Encinas, Undersecretary of the Interior and who heads the Truth Commission, condemned the leak through social networks and asked the prosecution to investigate who could be behind it. The official also pointed out that this type of leak could jeopardize the investigation process into the Ayotzinapa case 8 years after the events. Karina Maciel contributed to this report.