The paratroopers had their assignment: Check out reports that Afghan police had recovered the mangled remains of an insurgent suicide bomber. Try to get iris scans and fingerprints for identification.

The 82nd Airborne Division soldiers arrived at the police station in Afghanistan’s Zabol province in February 2010. They inspected the body parts. Then the mission turned macabre: The paratroopers posed for photos next to Afghan police, grinning while some held — and others squatted beside — the corpse’s severed legs.

A few months later, the same platoon was dispatched to investigate the remains of three insurgents who Afghan police said had accidentally blown themselves up. After obtaining a few fingerprints, they posed next to the remains, again grinning and mugging for photographs.

Two soldiers posed holding a dead man’s hand with the middle finger raised. A soldier leaned over the bearded corpse while clutching the man’s hand. Someone placed an unofficial platoon patch reading “Zombie Hunter” next to other remains and took a picture.

The Army launched a criminal investigation after the Los Angeles Times showed officials copies of the photos, which recently were given to the paper by a soldier from the division.

“It is a violation of Army standards to pose with corpses for photographs outside of officially sanctioned purposes,” said George Wright, an Army spokesman. “Such actions fall short of what we expect of our uniformed service members in deployed areas.”

Wright said that after the investigation, the Army would “take appropriate action” against those involved. Most of the soldiers in the photos have been identified, said Lt. Col. Margaret Kageleiry, an Army spokeswoman.

The photos have emerged at a particularly sensitive moment for U.S.-Afghan relations. In January, a video appeared on the Internet showing four U.S. Marines urinating on Afghan corpses. In February, the inadvertent burning of copies of the Koran at a U.S. base triggered riots that left 30 dead and led to the deaths of six Americans. In March, a U.S. Army sergeant went on a nighttime shooting rampage in two Afghan villages, killing 17.

The soldier who provided The Times with a series of 18 photos of soldiers posing with corpses did so on condition of anonymity. He served in Afghanistan with the 82nd Airborne’s 4th Brigade Combat Team from Ft. Bragg, N.C. He said the photos point to a breakdown in leadership and discipline that he believed compromised the safety of the troops.

He expressed the hope that publication would help ensure that alleged security shortcomings at two U.S. bases in Afghanistan in 2010 were not repeated. The brigade, under new command but with some of the same paratroopers who served in 2010, began another tour in Afghanistan in February.

U.S. military officials asked The Times not to publish any of the pictures.

Capt. John Kirby, a Pentagon spokesman, said the conduct depicted “most certainly does not represent the character and the professionalism of the great majority of our troops in Afghanistan.... Nevertheless, this imagery — more than two years old — now has the potential to indict them all in the minds of local Afghans, inciting violence and perhaps causing needless casualties.”

Kirby added, “We have taken the necessary precautions to protect our troops in the event of any backlash.”

Times Editor Davan Maharaj said, “After careful consideration, we decided that publishing a small but representative selection of the photos would fulfill our obligation to readers to report vigorously and impartially on all aspects of the American mission in Afghanistan, including the allegation that the images reflect a breakdown in unit discipline that was endangering U.S. troops.”

The photos were taken during a yearlong deployment of the 3,500-member brigade, which lost 35 men during that time, according to icasualties.org, a website that tracks casualties. At least 23 were killed by homemade bombs or suicide bombers.

Suicide attacks on two bases of the brigade’s 1st Battalion, 508th Parachute Infantry Regiment killed six U.S. soldiers and four Afghan interpreters. The platoon whose soldiers posed for the photos was part of the battalion.

The soldier who provided the photos, and two other former members of the battalion, said in separate interviews that they and others had complained of inadequate security at the two bases.

An Army investigation into a July 2010 suicide attack in Kandahar that killed four U.S. soldiers found that senior members of the battalion had complained about security. But it concluded that force protection measures were “reasonable and prudent” in the face of limited resources.

Virtually all of the men depicted in the photos had friends who were killed or wounded by homemade bombs or suicide attacks, according to the soldier who provided the images. One paratrooper on the mission wore a bracelet bearing the name of a fallen comrade.

On the first mission, to the police station in the provincial capital of Qalat, Afghan police told the platoon that the severed legs belonged to a suicide bomber whose explosives detonated as he tried to attack a police unit, according to the soldier who provided the photos.

On the second mission, to the morgue in Qalat in late April or early May 2010, Afghan police told the platoon that explosives had detonated as three insurgents were preparing a roadside bomb.

The platoon was able to obtain some fingerprints from the corpses for a database maintained by U.S. forces, the soldier said.

The soldiers felt a sense of triumph and satisfaction, especially after learning that the insurgents had been killed by their own explosives, he said.

“They were frustrated, just pissed off — their buddies had been blown up by IEDs” — improvised explosive devices — the soldier said. “So they sort of just celebrated.”

The Qalat photos were circulated among several members of the platoon, the soldier said, and soldiers often joked about them. Most of the soldiers in the photos were low-ranking — including six specialists or privates.

Col. Brian Drinkwine, then-commander of the 4th Brigade, and Lt. Col. David Oclander, then-commander of the 1st Battalion, said they were not authorized to comment on the photos.

The Pentagon declined a Times request that Army officials contact all active-duty soldiers in the photos to provide an opportunity to comment. The Times sent requests for comment by email and Facebook to seven soldiers in the photos. One, now serving in Afghanistan, declined to comment. The others did not respond.

The photos were taken during a tumultuous period in the brigade’s deployment.

In January 2010, the commander of the brigade’s 2nd Battalion and the battalion’s top noncommissioned officer were relieved of duty and ordered home after slides with racial and sexist overtones were shown during daily PowerPoint briefings.

Separately, an Army investigation criticized Drinkwine for failing to prevent his wife from threatening and harassing some unit officers and their spouses during the deployment.

Ft. Bragg’s commanding general, Lt. Gen. Frank Helmick, told the Fayetteville Observer in June 2010 that Drinkwine had created “a dysfunctional situation” in the unit. Drinkwine remained in command until after the deployment ended that August.

david.zucchino@latimes.com