Zayda Peña, the 28-year-old lead singer of grupero band Zayda y Los Culpables, was shot to death in a hospital emergency room in Matamoros, Mexico, on Dec. 1.

The singer was in the hospital after being shot the day before in a motel room in the same city near the Texas-Mexico border, according to published reports. A friend of Peña's and a motel manager died in that shooting. An assassin reportedly entered the hospital where Peña was recovering from surgery, and fatally shot her.

No arrests had been made at deadline. Peña's many albums on Musart/Balboa include "Atrévete,” "Estoy Enamorada,” “Sensible,” "Caída Libre” and “Como Mariposa,” which produced the single "De Contrabando," a cover of which later became a hit by Jenni Rivera. Peña’s album “Sola” contained the hit “Tiro de Gracia.”

In a statement, Balboa Records and its Mexican label, Discos Musart, lamented “the tragic death of its artist Zayda, and shares this pain with her family and fans, to whom they extend sincere condolences.

“Her recordings are left as a legacy to us. We will remember her as a disciplined, professional singer, a figure in the grupero movement in which she displayed her sensitivity and character, always true to her roots.”

Frank White, VP of operations/promotions director at Balboa Records, says Peña's career had been "on hold" in recent years, but noted that she had been working on new material.

Regional Mexican singers have been high-profile targets in many unsolved shootings, including the one that killed banda star Valentin Elizalde late last year.