Deputies at the Brazoria County Detention Center found Arthur Bautista and gave him medical treatment, according to the sheriff's office.
Bautista was pronounced dead at the hospital shortly after midnight.
He had been in custody since March 25, 2024, on charges of possession of a controlled substance and criminal trespassing.
The Texas Rangers are investigation the in-custody death, which is protocol.
The medical examiner has not yet determined how he died.
The sheriff's office confirmed Bautista's death on July 29, roughly a week after it happened.