Shortly before midnight on December 1, 2007, an unknown gunman shot Peña in the back at Mónaco Motel in Matamoros, Tamaulipas, across the U.S.-Mexico border from Brownsville, Texas.
[3] Paramedics took Zayda to Alfredo Pumarejo Hospital in Matamoros, where doctors determined that her injuries were not fatal.
Physicians placed Peña in emergency surgery in order to remove the bullet.
[3] Once they were able to find Zayda, the assailants went in and shot her again in the chest at point blank range to ensure her death.
Her mother, Blanca Aidé Arjona, works in the office of a public prosecutor as of 2007.