A second person has been arrested in the death of a 1-year-old boy who died after he ingested a mixture of fentanyl and heroin in a Bronx apartment last year.

Twenty-nine-year-old Chayanne Mendez Rodriguez was arrested Saturday on a murder charge. It's not clear if he has an attorney who can speak for him.

Police say Mendez Rodriguez was present when little Darwin Gonzalez-Santana somehow consumed the drugs that killed him last December.

Darwin's mother, Daira Santana-Gonzalez, was arrested in May and charged with murder in her son's death. Police said the family's apartment was being used to package drugs.

Santana-Gonzalez told the Daily News in a jailhouse interview earlier that she loved Darwin and would never do anything to hurt him.

Police are still seeking the child's father.