Among experts on the American-led team investigating Iraq's mass graves, the skeletal remains lying face-up at the rear of the tangled grave here have been given a name — the Blue Man — that speaks for a sorrowful familiarity developed by some of those who work with victims of mass murder.
But more than his blue shirt, and his blue-striped trousers, what distinguishes the remains is the way they speak for the terror of death under Saddam Hussein. The man was thrown backward by automatic weapons fire, his eyes blindfolded and his arms tied behind his back, his skull jerked upward at the neck, his fleshless mouth gaping, his two rows of teeth stretched apart, as though in a primal scream.
Together, in the late winter of 1991, at least 28 men were executed here, crowded together in a pit their killers scraped with a backhoe from the desert floor. Rounded up along the alleyways of their native city, they were forced aboard a bus or truck and driven out along an isolated highway.
After barely half an hour's journey, the grim caravan turned down a bumpy track, halting just far enough into the desert for gunfire to be muffled from passing traffic.
The end would have come quickly, the forensic experts said, victims stumbling out of the vehicle, herded into the pit, then pushed forward into a shallow cut not much wider or longer than a stretch limousine. At the last moment, judging by the pile of bodies, the victims surged backward, perhaps in terror at the sound of rifles being readied for fire.
Among the bodies, the experts have located at least 80 spent cartridges from Kalashnikov rifles, which were the weapon of choice among the killers of Mr. Hussein's secret police.
Michael Trimble, who is called Sonny, the leader of the mass-graves team that set up camp beside an escarpment in Iraq's western desert last month, is a 53-year-old forensic archaeologist from St. Louis. He is a veteran of other sites of mass killings around the world, on assignment from a civilian post with the Army Corps of Engineers.
Standing above the pit where the desert victims died, he said the 120-member team here, now in their third week of excavation and examination of two mass-grave sites, were sustained through days of punishing 130-degree heat by an urge to bring justice for the victims.
"When you work with these people for some time," he said, referring to the remains, "you get real attached to them, you feel real bad about what happened to them, and you want to do whatever you can to bring their killers to account."
What happened here is not only a macabre marker in the history of Iraq under Mr. Hussein, but a harrowing footnote in American politics. The victims here, American and Iraqi officials say, died in Mr. Hussein's suppression of the Shiite uprising across southern Iraq in early 1991. It was a rebellion that survivors — and American critics of the President George H. W. Bush — say that the president encouraged after halting American troops at Iraq's southern border with Kuwait at the end of the Persian Gulf war.
For years, Middle East experts have debated Mr. Bush's role in encouraging Iraq's Shiites and Kurds to mount a challenge to Mr. Hussein after the war over Iraq's invasion of Kuwait ended, before ruling out American military action to halt the mass killings of Shiites that Mr. Hussein initiated to crush the uprising. Mr. Bush himself has said that what happened to the Shiites was one of the deepest regrets of his presidency.
For the American forensic experts who came to Iraq after the 2003 invasion, the desert camp is a way station toward holding Mr. Hussein accountable for what many Iraqi human rights experts say was the most merciless passage in his 24 years in power.
Raid Juhi, chief investigative judge for the Iraqi court now trying Mr. Hussein in another case, said during a visit here on Saturday that the court had documentary evidence, and statements from witnesses, showing that at least 100,000 Shiites, and possibly 180,000, died in the 1991 repression.
The trial of Mr. Hussein and his associates for what is known among the Shiites as the "intifada," or rebellion, could be still a year or more off.
The Iraqi tribunal has only one courtroom, in Mr. Hussein's old Baath Party headquarters in Baghdad. The first trial in a series planned for the ousted Iraqi dictator, involving the brutal aftermath of a failed assassination attempt in 1982 against Mr. Hussein in the mainly Shiite town of Dujail, is not expected to end before late summer.
The tribunal will then hear a second case, involving accusations that 50,000 Kurds were killed in what is called the Anfal offensive, which reached its peak in 1988.
Concerned about a possible insurgent attack, American officials who brought two reporters to the desert grave site on Saturday, aboard an American military helicopter, insisted the location not be pinpointed. On the flight from the Green Zone command compound in Baghdad to the grave site, the Black Hawk helicopter passed over some of the most hotly contested territory in the war.
The forensic team of Americans, Australians and other nationalities works under heavy guard, wary of attack by insurgents driven by loyalties to Mr. Hussein.
The proximity of the rebel threat here echoes the events of 1991, when Mr. Hussein, in Baghdad, quickly marshaled the death squads that spread out across Iraq's southern provinces to extinguish the Shiite uprising. Of the 200 mass graves the Iraqi Human Rights Ministry has registered in the three years since the American-led invasion, the majority are in the south. One, at Mahawil, about 50 miles south of Baghdad, is believed to hold as many as 10,000 to 15,000 victims, Mr. Juhi said.
Two other sites, one at Hatra, near Mosul in the north, and another at Muthanna, near the southern city of Samawa, have been exhaustively examined by Mr. Trimble's team. The remains of more than 300 victims from those locations, killed during the Anfal campaign, are stored in chilled containers at a high-technology laboratory at the Baghdad international airport.
The desert site here will be studied for another week or two, with the remains that are found flown to Baghdad for further testing.
The Americans were drawn to the desert site initially by satellite imagery pointing to about 200 sites in the area where desert undulations suggested there could be mass graves. Reconnaissance teams brought the focus down to 18 sites, and 2 of those are under excavation. Work has just begun at the second, at the entrance to a deep ravine on the escarpment's edge. Team members say bone fragments, skulls, clothing and spent cartridge cases point to at least 10 victims, possibly more, beneath sediment that winter rains have washed into the ravine.
The larger of the two sites, where the man in the blue shirt and trousers was killed, is a ghastly tableau of what summary execution under Mr. Hussein involved. Kerrie Grant, 45, an Australian forensic archaeologist, said all the victims appeared to be male, and between the ages of 20 and 35.
Mr. Juhi, the Iraqi judge, said the 1991 killers spent little time hunting down those responsible for the uprising, seizing young men of fighting age at random and executing them without trial, in an act of calculated terror.
The victims lie in a huddled group, some thrown backward, some to the side, others collapsed atop one another, their legs buckled beneath them, with telltale rips in their clothing showing where bullets struck their chests and stomachs, others with leg bones shattered by gunfire.
Some, including the Blue Man, who had rips in his clothing at one shoulder and in the chest, had bullet holes in their skulls as well, as if they might have survived the first volley and been killed by follow-up shots to the head.
The frayed remains of blindfolds, some fashioned from torn swatches of colored cotton, some from checkered, Bedouin-style headdresses known as kaffiyehs remained wrapped around skulls still matted with tangled hair.
Among most of the fully unearthed bodies, the wrist bones met together behind the victims' backs, with fragments of rope and cloth used to tie them mingled with the earth-stained bones. The forensic experts say still more bodies, lying beneath the visible ones, may be exposed when the remains of the 28 men at the pit's surface are lifted into body bags and taken away.
Ms. Grant, the Australian expert, and Mr. Juhi, the Iraqi judge, said there were signs that the victims were hurriedly seized at their homes, possibly at night, and given no time before being taken to their deaths. Heavy jackets and layered clothing — including one man's sweater beneath his flowing dishdasha robe — pointed to the killings having occurred in the early days of the uprising, in March 1991, when there was still winter weather in this part of Iraq, they said.
A scattering of plastic flip-flops and sandals, and the fact that some victims arrived here barefoot, was further evidence that the men were surprised by their killers, they said.
Mr. Trimble, the leader of the mass graves team, said little he found here surprised him after a lifetime of studying violent death. "I believe most human beings operate on a least-effort basis, and murderers certainly do," he said. "The men who killed all these people came down this road, and they did what all mass murderers do — they dug deep, they killed their victims quickly, they covered them up and then they left, as quickly as they came."