The relics of obscure Roman martyr St. Datian are encased in a wax effigy in the relic chapel to the right of the altar at the Church of the Most Holy Redeemer.

They were sent to the church in 1892 when a wealthy Italian woman could no longer afford to keep them in her private chapel. She donated them to avoid their seizure by the Italian government. There were rumors that the bones of the martyr were actually the bones of a policeman who was shot defending the church from burglars but the parish denies this.

The relic chapel also features small relics from over 150 other saints.