Seven-year-old Monica and her two-year-old brother, Victor were last seen at their home in Yuba City, California on July 26, 1999.
The kids' mother Blanca Alicia Duenas Arellano was found murdered in the bedroom of the family's residence in the Park Terrace apartment complex in the 600 block of Queens Avenue. She was stabbed multiple times with a butcher knife which was left with her body.
The prime suspect in Blanca's murder is her estranged husband, Francisco Arellano. He is the father of Monica and Victor, but is not related to Blanca's other three children.
Francisco disappeared after Blanca's murder and authorities believe that he took Monica and Victor and ran.
The couple's relationship had been troubled and in 1997, Blanca had gotten a restraining order against him claiming that he'd abused her for years. She said that Francisco threatened to kill her and take their children to Mexico.
Francisco's birthdate is September 17, 1971. He was 27 years old in 1999. He is described as Hispanic, 5'7 tall and 140 pounds with brown eyes and black hair. He may be driving a Chevrolet Monte Carlo.
Based on his prior threats, investigators believe that Francisco, Monica and Victor may be in Mexico. They have not been heard from since.