Delegation traveled to Mexican border city on May 6
Measure overwhelmingly passed in Mexico state's Congress on April 21
Officials from across region attended launch in Mexico City
Guanajuato Civil Registry issued document to activist on Feb. 11
Julissa Ramírez and Nohemí Medina Martínez killed earlier this month
Julissa Ramírez and Nohemí Medina Martínez killed in Ciudad Juárez
New policy announced Wednesday in Mexico City