Atlanta, Georgia (CNN) -- Tapes obtained by CNN of interrogations of a group of U.S. servicemen charged with unprovoked killings of Afghan civilians describe gruesome scenes of cold-blooded murder.

"So we met this guy by his compound, so Gibbs walked him out, set him in place, was like standing here," says Cpl. Jeremy Morlock, detailing how, on patrol earlier this year and under the command of his sergeant, Calvin R. Gibbs, he and others took an Afghan man from his home and killed him.

"So, he was fully cooperating?" the military investigator asks on the tapes in a May 2010 interview.

"Yeah," Morlock responds.

Investigator: "Was he armed?"

Morlock: "No, not that we were aware of."

Investigator: "So, you pulled him out of his place?"

Morlock: "I don't think he was inside. He was by his little hut area ... and Gibbs sent in a couple of people."

Investigator: "Where did they stand him, next to a wall?"

Morlock: "Yeah, he was kinda next to a wall ... where Gibbs could get behind a wall when the grenade went off. And then he kind of placed me and [Spc. Adam] Winfield off over here so we had a clean line of sight for this guy and, you know, he pulled out one of his grenades, an American grenade, popped it, throws the grenade and tells me and Winfield, 'Alright, wax this guy. Kill this guy, kill this guy.'"

Investigator: "Did you see him present any weapons? Was he aggressive toward you at all?"

Morlock: "No, not at all. Nothing, he wasn't a threat."

Morlock is accused of killing three Afghan civilian men -- two by shooting -- between January and May of this year. The third was the killing he described above.

The charging papers from the U.S. military paint a picture of a band of rogue soldiers, smoking hash, bored and plotting and carrying out murders of Afghan civilians for sport.

Gibbs is also accused of having kept fingers and leg bones as souvenirs, according to the documents. A soldier who tried to blow the whistle was beaten and threatened, some soldiers said.

Some of the soldiers took photographs of each other next to the Afghans after they had been shot, CNN has learned.

According to the military documents, some of the soldiers were involved in throwing grenades at civilians.

Morlock's civilian attorney, Michael Waddington, did not deny that his client killed for sport. "That's what it sounds like," he told CNN.

Waddington said his 22-year-old client was brain-damaged from prior IED attacks, was using prescription drugs and smoking hashish and was under the influence of and in fear of his commanding officer, who is also charged. He called Gibbs "the ringleader behind this."

Authorities allege Gibbs kept finger bones, leg bones and a tooth from Afghan corpses. Another soldier allegedly kept a skull from a corpse, according to charging documents.

Gibbs' attorney did not return CNN's calls.

Several soldiers are charged with taking pictures of the corpses, and one soldier is charged with with stabbing a corpse.

Other soldiers charged said they were afraid of Gibbs and admitted smoking hashish laced with opium nearly every day.

Cpl. Emmitt Quintal, who is charged with trying to interfere with a military investigation and drug abuse, told the Army investigator the whole deployment was using drugs on "bad days, stressful days, days when we needed to escape."

Quintal told investigators in May that the platoon -- under Gibbs' direction -- went to the barracks of a man who they believed was a snitch and beat him up.

After the beating, Quintal said on the tape, "Gibbs sat down casually and told [him] if he snitched again he would kill him and that he had killed people before and that he had no problem killing again. At that time, Sgt. Gibbs had a cloth. He opened it and dropped it and three human body fingers fell on the ground. At that point, I really lost my head."

Quintal's attorney did not return a call from CNN.

In all, Morlock is charged with three counts of murder. He is accused of killing Afghan civilian Gul Mudin in January with a grenade and rifle; killing civilian Mullah Adahdad in May in a similar manner; and shooting to death Marach Agha in February.

On Monday, Morlock and his attorney attended an Article 32 hearing at Joint Base Lewis-McChord in Washington.

At the hearing, to determine whether the military has enough evidence against Morlock to proceed with a court-martial, Army Special Agent Anderson D. Wagner testified that Morlock admitted in interrogations last May to being involved in the murders.

In his client's defense, Waddington suggested that Morlock was under the influence of drugs when he spoke with Wagner and that he should not have been interviewed until a later time. Morlock was being transferred through Kandahar for assessment of traumatic brain injury when the interview took place, Waddington said.

But Wagner testified that Morlock appeared lucid and articulate during the interview.

Still, Wagner acknowledged that there was no direct evidence Morlock was responsible for the killings, since no autopsies were performed.

Adam Kelly, another soldier under Gibbs, told investigators that the staff sergeant had a stash of guns and other items that could be planted on murder victims and that the other soldiers feared him.

"If Gibbs knew I was sitting here in front of this camera right now, there is no doubt in my mind that he would [expletive], that he would take me out," he said.

Kelly himself is not charged with murder. His attorney did not return a call from CNN.

The Pentagon has not commented on any of the cases. Instead, it sent CNN a statement about the videos:

"Disclosure of the video recordings to the public at this juncture is troubling because it could adversely affect the fair and just administration of the military justice process," the statement says.

Pretrial investigation hearings for five of the soldiers are scheduled over the next several weeks. Seven other soldiers are facing lesser charges, ranging from covering up the killings and mutilating corpses to drug use.

All of the men were members of a 2nd Infantry Division brigade operating near Kandahar in southern Afghanistan in 2009 and 2010.

The five facing murder charges are Morlock of Wasilla, Alaska; Staff Sgt. Calvin Gibbs, of Billings, Montana; Pfc. Andrew Holmes of Boise, Idaho; Spc. Adam Winfield, of Cape Coral, Florida; and Spc. Michael Wagnon, of Las Vegas, Nevada. They are all from the 5th Stryker Brigade.

Winfield's attorney, Eric Montalvo, told CNN in an e-mail that his client "is not guilty of premeditated murder, and that's as clear as I can be."

He said the videotape "doesn't tell the whole story. ... It is sort of what they molded him into."

CNN's Kathleen Johnston, Courtney Yager, Scott Zamost and Todd Schwarzschild contributed to this story.