The mother of an 8-year-old Guatemalan boy who died in U.S. custody has spoken out as immigration authorities scramble to counter criticism over the death—the second of a migrant child in less than a month. A cause of death has yet to be determined for Felipe Gomez Alonzo, who died late Christmas Eve after spending several days in U.S. Customs and Border Protection custody. “I’m sad and in despair over the death of my son,” the boy's mother, Catarina Alonzo, 32, told Reuters in a phone interview from her home in Yalambojoch, speaking through a translator. Gomez’s parents are asking authorities to complete an autopsy as quickly as possible so the boy's body can be returned to Guatemala. The boy had reportedly trekked to the U.S. with his father from Nenton in Guatemala’s Huehuetenango province, an area known for its high rates of migration. His death came about two weeks after Jakelin Caal, a 7- year-old girl from Guatemala, died after her temperature reached 105.7 degrees Fahrenheit in U.S. custody. U.S. Department of Homeland Security Secretary Kirstjen Nielsen said in a statement Wednesday that all children in Border Patrol custody are given a “thorough medical screening,” but will now receive “a more thorough hands-on assessment” after being apprehended, whether or not the adult with them asks for one, Reuters reports.