In 2016, staff of the Specialized Sub-Attorney General’s Office for Organized Crime Investigation (SEIDO) of the Attorney General’s Office of Mexico (PGR), now the Specialized Prosecutor’s Office for Organized Crime (FEMDO) of the Attorney General’s Office of Mexico (FGR), illegally investigated and used targeted surveillance against human rights defenders Ana Lorena Delgadillo, Marcela Turati, and Mercedes Doretti, in relation with their work with relatives of missing migrants in San Fernando, Tamaulipas. We urge Mexican authorities to stop any arbitrary and illegal investigation, targeted surveillance, and criminal action against them.