On the right side wall is a fresco by Giovanni Battista Pozzo, of the martyrdom of St. Eleutherius, Bishop of Illyria (2nd century). He suffered his martyrdom under Emperor Commodus (180-192 A.D.). Notice that the restoration of the fresco is incomplete.

St. Eleutherius is often confused with Pope Eleuterus, the 12th successor of St. Peter, who, traditionally, was buried in this chapel.