In 2014, Mirna Nereida Medina Quiñónez began to search for her missing son, Roberto Corrales. In El Fuerte, Sinaloa, she led a group of searchers called Las Rastreadoras, the trackers. In September 2016, La Jornada reported that the group had grown from about 30 people to almost 300, and that it had found about 60 bodies in at least 50 graves. (Video in Spanish.)
She said: “Me hice rastreadora porque el gobierno no investiga y porque aquí la policía está metida en la mayoría de los casos” (I became a tracker because the government does not investigate, and because here the police are involved in most cases).
In April 2026, Uno TV reported that more than 200 search collectives were registered in 2024. Andrea Horcasitas of the Universidad Iberoamericana called it “una cifra conservadora” (a conservative figure).