A recent study by Dr. Stephen Greenspan, Clinical Professor of Psychiatry at the University of Colorado, revealed that throughout American history at least 106 individuals have been granted posthumous pardons, including 12 individuals who were executed. Although not all of the pardons were granted because of doubts about the defendant’s guilt, Dr. Greenspan found that in many instances the defendant was proven, or was very likely, not guilty and had originally received biased or unfair legal proceedings. Among those who were executed and later pardoned were Joe Arridy in Colorado (pardoned in 2011), Lena Baker in Georgia (pardoned 2005), and four men in Illinois who were hanged for their participation in the Haymarket Square riot in 1886 (pardoned 1893). Other reasons for the pardons included a change in political, moral or legal climate, or as a reward for exemplary character. The author participated in the effort to win a pardon for Joe Arridy and noted that recent cases of innocence may have spurred an increase in posthumous pardons.

(S. Greenspan, “Posthumous Pardons Granted in American History,” March 2011). See Clemency and Executed but Possibly Innocent.