A human skull found in rural Southern California in 1991 has been identified through DNA testing as the remains of a missing boy, authorities said. The skull belonged to 4-year-old Derrick Burton, who was reported missing that same year, the San Bernardino County Sheriff’s Department said in a press release last week.

A quail hunter found the skull on the outskirts of Mentone, a small community about 65 miles east of Los Angeles. Investigators also found a trash bag with decomposition odor and children’s clothing, the department said.

A coroner determined the skull was from a child 4 to 8 years old but the cause of death was not determined and the case went cold.

DNA testing last year led to distant genetic relatives in Houston, Texas, officials said. The relatives provided DNA that led to the boy’s mother, Patricia Clark, who had reported him missing to police in the city of San Bernardino, the department said.

Clark’s DNA was obtained and it was determined that “Clark was a 100% parental match to the human remains of the child Doe, now known to be Derrick Burton,” the sheriff’s office said.

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Homicide detectives are continuing the investigation.

Anyone with information is asked to contact the Specialized Investigations Division – Homicide Detail, Cold Case Team, at (909) 890-4904.