Leahy, 28, was convicted in February and sentenced to life, with eligibility for parole after 20 years. Four codefendants, including two superiors, also were convicted or pleaded guilty.
Master Sgt. John E. Hatley, 40, of Texas was convicted of premeditated murder and sentenced to life with the possibility of parole. Sgt. 1st Class Joseph P. Mayo, 27, of North Carolina pleaded guilty to the same offense and received 35 years with the possibility of parole. Two other soldiers, convicted of lesser crimes, received lighter sentences. All were from the Army's 1st Battalion, 18th Infantry Regiment.
To Iraqis, reports of abuse and extrajudicial killings by American soldiers are met with outrage and demands for severe punishment.
But to Leahy's friends and family in Illinois, his sentence was far too harsh. To them, the incident illustrates how soldiers in the heat of combat can confuse right and wrong.
Leahy, known as "Mickey," had a typical suburban upbringing, friends and family say. He played football and baseball in high school, graduating in 1999.
By the time he joined the Army in 2003, he had become interested in medicine and thought the military could give him the structure and training to make it a career.
He had planned to transfer to an Army Rangers training school in Georgia and later become a physician's assistant in Texas, family members said. He was wrapping up his second tour in Iraq at the time of the incident.
Now, he is imprisoned at the U.S. Disciplinary Barracks at Ft. Leavenworth, Kan.
But his friends and family live in hope -- and at least some of their wishes have come true.
Earlier this month, a brigadier general granted Leahy clemency, reducing his sentence to 20 years with parole eligibility after seven, according to Army officials. His discharge was upgraded from "dishonorable" to "bad conduct."
Leahy could serve even less time if his attorney can persuade the Army Clemency and Parole Board that he suffered from combat stress and fatigue and was following the lead of higher-ranking soldiers against suspected militiamen who had attacked his troops.
Army officials refused to discuss Leahy's case or explain the latest ruling.
But they said a clemency review is triggered when soldiers are convicted of crimes and sentenced to more than a year in jail.