The Kimball County grand jury convened Nov. 9 to review the death of Jesus Estrada-Perez, of Minnesota.
Authorities say Estrada-Perez hung himself on Aug. 1, one day after he was arrested on drug charges during a traffic stop. He was hospitalized and died a few days later.
Authorities say his traveling companion told them that Estrada-Perez suffered from depression and anxiety and may have been suicidal.
Nebraska law requires that a grand jury be convened when an inmate dies in custody.