I'd like to hear from Michael Leahy's family. He was somewhat framed for the murders. Besides that these soldiers don't get the correct training.

Michael and his family probably witnessed everyone else getting short sentences and dishonorable discharges and simply went along with it all. He didn't act alone.

U.S. soldier gets eight months in Iraq killings (click title to entry - thank you)
25-year-old pleads guilty to charges linked to murders of four prisoners

...Ribordy testified that he had helped stand guard as the prisoners were killed by other members of his patrol in early 2007. He said he approached the scene after the shots were fired and saw three bodies lying in a pool of blood, and then the fourth already in the canal.
Ribordy told the court he saw three other members of the patrol — Sgt. John E. Hatley, Sgt. 1st Class Joseph P. Mayo, and Sgt. Michael P. Leahy Jr. — at the scene and smelled gunpowder in the air.
"They all seemed calm," he said....

...In closing arguments earlier, Leahy's civilian lawyer, Frank Spinner, argued that Leahy went along with the killings because he was dazed from a lack of sleep and numb from being in a war zone for months. It was a sentiment bolstered on Thursday in testimony from Col. Charles Hoge, a doctor and director of psychology and neuroscience at the Army's Walter Reed Army Institute of Research.
He testified that Leahy was unable to reason properly because of the constant danger of living and operating in a war zone and getting little sleep for months on end.
"The tragedy resulted not so much by design but rather the working of fear, danger and madness attendant on many combat operations," Spinner said in his closing arguments.
The Iraqi prisoners were taken to the U.S. unit's operating base in Baghdad for questioning and processing, although there wasn't enough evidence to hold them for attacking the unit.(click here) (Paranoya set in and they saw themselves 'being lucky' to have lived through the attack THIS TIME, but, were worried that they would not live through the next attack if the prisoners were to be let go. They were tired and decided to protect themselves regardless of what their 'processing' produced.) Later that night patrol members took the Iraqis to a remote area and shot them in retribution for the attacks against the unit, according to testimony....

Everybody forgets this occurred for a reason. These soldiers weren't joy riding in a Humvee and decide '...today we are going to kill some Iraqis...." They were attacked before this occurred and were seeking to secure the area.

Basically, they either didn't believe any of the detainees, because of what they knew, or they didn't have command of the language and/or felt any translation was incorrect. They didn't want to be attacked again and decided to secure the area regardless of regulations for whatever reason existed.

They might have been worried that if released the enemy now, the detainees knew where they were and how better to kill them.

A lot goes on in a soldier's mind, not all of it rational when fatigue sets in. I don't believe any of this was handled well.