In this April 19, 2015 photo, Maria Guadalupe Gomez Hernandez, accompanied by her mother, swabs the inside of her cheek to submit a DNA sample to aid in the search for her missing brothers, in Iguala, Mexico. The international outrage over the 43 missing college students of Ayotzinapa emboldened hundreds of other families from the state of Guerrero, and for the first time spoke of their misfortune, adding the names of their loved ones to the government’s growing registry of 25,000 people reported missing nationwide since 2007. (AP Photo/Dario Lopez-Mills)