Some of the activities of the self-styled "kill team" are already public, with 12 men currently on trial in Seattle for their role in the killing of three civilians.

Five of the soldiers are on trial for pre-meditated murder, after they staged killings to make it look like they were defending themselves from Taliban attacks.

Other charges include the mutilation of corpses, the possession of images of human casualties and drug abuse.

All of the soldiers have denied the charges. They face the death penalty or life in prison if convicted.

The case has already created shock around the world, particularly with the revelations that the men cut "trophies" from the bodies of the people they killed.

An investigation by Der Spiegel has unearthed approximately 4,000 photos and videos taken by the men.

The magazine, which is planning to publish only three images, said that in addition to the crimes the men were on trial for there are "also entire collections of pictures of other victims that some of the defendants were keeping".

New documents released by the US Army paint a disturbing picture of depravity, deceit and savage internal discipline involving at least 12 Stryker soldiers from Washington during their recent deployment to Afghanistan.

The soldiers, all from the same company in the 5th Brigade, 2nd Infantry Division, are charged with a total of 76 crimes, including the premeditated murders of three Afghan civilians and the beating of one or more fellow soldiers.

One soldier is alleged to have stabbed a corpse last December.

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Gibbs also was allegedly one of the seven soldiers who participated in the May 5 beating of a fellow soldier. He threatened "to kill him if he spoke about hashish use within the platoon,'' according to charging documents.

On another occasion, the records allege Gibbs threatened to injure Winfield by saying: "I'm going to send you home by dropping a tow bar on you.'' He allegedly urged Winfield to lie to investigators about the civilian killings and drug use in the platoon, according to the documents.

Specialist Jeremy M. Morlock and four other American soldiers are accused in the killings of three Afghan civilians. Specialist Morlock could face a court-martial and a possible death sentence.

The solider was allegedly among the members of an American Army unit who, consumed with drug use, randomly chose Afghan civilians to kill and then failed to report the abuses out of fear they would suffer retaliation from their commander, according to testimony in a military court at Joint Base Lewis-McChord, Wash., on Sept. 27, 2010. Specialist Morlock, who grew up in Wasilla, Alaska, appeared in court but did not testify.

On the same day, a videotape in the case was leaked showing Specialist Morlock talking to investigators about the killings in gruesome detail with no apparent emotion..

At first blush, officers in the death-squad’s brigade may have been similarly lax. According to a detailed report on the brigade in December — shortly before the first killing — by Army Times‘ Sean Naylor, its commander, Colonel Harry Tunnell adopted the motto “Strike — Destroy” after his soldiers encountered heavier fighting than expected. It’s a long way from General Stanley McChrystal’s orders to protect Afghan civilians from harm.

Naylor reports that some of Tunnell’s frontline units were even more focused on killing perceived enemy than he was. “There’s definitely a disconnect between the platoon and company level and the battalion and brigade level,” an anonymous Charlie Company soldier told Naylor. That was not uniformly the case: Charlie Company’s commander, Captain Joel Kassulke, wanted to conduct more of a classic counterinsurgency mission. Tunnell yanked away Kassulke’s command after the company took heavy casualties. (Apparently this is a story that escaped the attention of marquee journalists who visited the brigade.)

The Monitor interviewed a dozen officers and officials who have served with Tunnell or who witnessed him leading troops in recent years. As active-duty members of the military, they could speak only on condition of anonymity because of Pentagon strictures against talking to the press without official clearance.

Some sources suggest that Tunnell set a tone that was not only out of line with Pentagon doctrine, but was inflammatory and potentially dangerous.

“When you feel violent intent coming down from the command and into the culture of the brigade, that’s when you end up with things like the rogue platoon,” says a senior US military official who worked with the brigade in early 2009 at the National Training Center before it deployed to Afghanistan. “He established a culture that allowed that kind of mindset to percolate. And there are second- and third-order effects that come with that. Clearly, the guys who were pulling the trigger are the proximate cause of the crime, but the culture itself is the enabler.”