Guillermina's mother dropped her off for visitation with her non-custodial father, Alejandro Villegas, on June 24, 1996. Alejandro did not return his daughter once the visitation period was up. Instead he called Guillermina's mother and asked her to resume their romantic relationship. When she refused, he fled with their daughter. A photograph and vital statistics for Alejandro are posted below this case summary. A felony warrant for interference with child custody was issued for the abductor on October 17, 1996. They may be in Mexico, possibly in the areas of Tetecala or Cuernavaca. Guillermina's case remains unsolved.

Some agencies state that Guillermina disappeared from Garland, Texas. That city's authorities are handling the investigation.