Max-Gian disappeared from Boise, Idaho on November 26, 2008. Authorities believe he was abducted by his non-custodial mother, Margaret Sanchez Mejia Dunbar Alcalde. Photographs and vital statistics for Margaret are posted below this case summary. A federal warrant for unlawful flight to avoid prosecution was issued for her on December 11, 2008. She is also wanted in Idaho for second-degree kidnapping.

Max-Gian's mother and his father, Marco Alcalde, married in Nevada in 1996. They moved to Idaho in 2005, then separated in 2007. Margaret was Max-Gian's primary caregiver during the marriage, while Marco worked to provide for the family. According to Marco, the catalyst for the divorce proceedings was him finding out through a neighbor that Margaret planned to take Max-Gian and go to the Dominican Republic, where she has family. After the Alcaldes separated, they shared custody of Max-Gian. The court noted that Margaret had made "baseless" accusations that Marco had a problem with alcohol, and that she had trouble getting Max-Gian to school on time; he had nine unexcused absences and was tardy twenty-six times when he was in kindergarten, and all of these occurred when he was in his mother's care.

On the morning of November 26, Marco dropped Max-Gian off at his elementary school, Collister Elementary. The child was supposed to stay with his mother for twelve days, and then Margaret would drop him off at school for Marco to pick him up. Margaret picked Max-Gian up at 1:00 p.m. and left his coat and backpack at school. Max-Gian had told his father that Margaret planned to take him to Nevada to visit friends of the family, but Marco was unable to get confirmation from Margaret about this. At 7:30 p.m., Max-Gian called his father and said he and his mother were at the airport and his older brother (Margaret's son from her first marriage) was going to pick them up. Max-Gian's older brother was a college student in La Mirada, California, so Marco believed Max-Gian must be at the Los Angeles Airport. Max-Gian said he would visit his brother, then go to Nevada to visit his friends. This was the last time Marco spoke to his son.

During the following days, Marco was unable to reach Max-Gian or Margaret by phone. He normally communicated with his son daily. On December 1, Max-Gian didn't arrive at school and Margaret didn't call to explain his absence. The following day the police began to investigate, but because of the joint custody arrangement there was little they could do. Marco was finally able to report Max-Gian missing on December 7, the day the child was supposed to return to his care. There have been no firm leads on Max-Gian's whereabouts since then. He and Margaret never visited their friends in Nevada.

According to Marco, Margaret also abducted her older son from her previous marriage in 1989. He was three years old at the time. She was living with the boy's father in Germany when she allegedly took him to southern California without his father's consent. Margaret has a Ph.D in Romance linguistics and literature and she speaks English, French, German, Spanish and Italian. She has taught Italian, English as a Second Language, and Pilates. Marco describes her as a cautious individual who may appear socially awkward or shy. She is a devout nondemoninational Christian and may associate with a Christian religious organization. She is in good physical condition and may visit a gym regularly and carry nutritional supplements. She likes fruit but avoids eating bread. Marco stated Max-Gian is a very social child. His favorite foods are chicken strips with French fries, chicken tacos and taquitos, green peas, raw carrots, pasta with olive oil and salt, and pancakes. He enjoys playing video games and all sports, riding his skateboard, playing with his toy light saber and other toy swords, playing with legos and dressing in costumes.

Marco stated Margaret prefers a warm climate and may be in southern California, Arizona, Hawaii, Florida, Mexico, the Caribbean, Central America or South America. He stated he had Max-Gian's passport, but it would be possible to go to Mexico without a passport. Marco describes his ex-wife as mentally unstable and he's afraid for Max-Gian's safety. The child's whereabouts are unknown and his case remains unsolved.