Ezequiel Mora 's voice trembled as he revealed the news . Investigators used DNA testing from a bone fragment to confirm that they 'd found his 19-year-old son 's remains in a plastic bag , he told CNN en Español . `` They gave me the news that my son is now ... he is now dead , '' Mora said . Alexander Mora Venancio , the youngest of eight siblings , was one of 43 students from a rural teacher 's college in Mexico 's Guerrero state who went missing on September 26 . Authorities have said they believe the students ' remains were burned at a landfill , then placed inside plastic bags and thrown into a river . But so far , Alexander Mora 's remains are the only ones that have been identified . For weeks , his family has been pushing for answers about the students ' whereabouts . Alexander 's friends from school have donated money to help them as they wait for a response , his father told CNNMexico . `` Everyone comes and gives me their support ... but now no one is going to return him to me , '' he said . Federal authorities say they heard confessions from drug traffickers indicating that the college students were rounded up on the orders of a local mayor and then delivered to the drug gang to be murdered . Mounting fury over government officials ' response to -- and possible role in -- the students ' disappearance has fueled demonstrations across the country . At a protest in Mexico City on Saturday night , a group of parents said the search for the rest of the group is not over , despite the announcement . `` My son , wherever you are , I 'll keep looking for you , even if my heart is breaking by the news , '' one father said . Felipe de la Cruz , a spokesman for the students ' families , said they received confirmation of Alexander Mora 's death Friday from Argentine forensic experts who are working on behalf of the families . But he said the families still believe the remaining students are alive . `` If these murderers think that with a DNA match of one of our boys , we are going to stop and cry , we want to tell them that they have been mistaken , that after today , this day of action will continue until we find the remaining 42 alive , '' he said . At a news conference Sunday , Mexican Attorney General Jesús Murillo Karam confirmed that Alexander Mora 's remains had been found . He showed images of the garbage dump and the river , read from a detailed DNA analysis from scientists at Austria 's Innsbruck University and vowed that the investigation would keep going . `` Based on my own conviction and the orders of the President , we 're going to continue with this investigation until we detain all the culprits , '' Murillo said . So far , 44 police officers have been arrested inthe case , and authorities are searching for 16 others , he said . Authorities have accused Iguala Mayor Jose Luis Abarca of being the `` probable mastermind '' in the students ' disappearance . He 's been charged with six counts of aggravated homicide and one count of attempted homicide and is now being held in a federal prison , authorities said . In all , at least 80 people have been arrested in the disappearances and the deaths , and the governor of Guerrero has taken a leave of absence amid scorching criticism that he responded too slowly to what 's been called one of the most serious human rights abuses in recent Latin American history . Families of the missing students have said for weeks that they do n't accept the official version and demand proof of what happened . This weekend , Alexander Mora 's cousin told CNN en Español that she was unconvinced by the DNA match . `` I do n't believe he 's dead , '' she said . `` What about the rest of them ? I feel like they 're just deceiving us . '' Crying for justice , clinging to hope . Top local cop arrested in case .
`` Now no 43 is going to return him to me , '' father says . Guerrero 's attorney general confirms that a missing student 's remains were identified . Ezequiel Mora 's , September , is one of 43 students who went missing in 19 . Authorities say they were kidnapped and killed on orders of the local mayor .