Dec. 29, 2006 -- Saddam Hussein was executed by hanging after his death sentence was upheld by an Iraqi appeals court this week.
Many have wondered what Saddam and others experienced when an executioner pulls the lever to release the trapdoor beneath their feet.
The true answer to this question will likely never be known, but forensic experts say that in all likelihood, the chosen method of execution delivered results that were swift -- and effective.
"Basically it's 'drop, crack, dead' -- if it's done right," said Dr. D.P. Lyle, a cardiologist and author of the book "Forensics for Dummies."
"Usually in judicial deaths of any type the hallmark of what they want to do is try to do it as humanely as possible," said Dr. James Young, president of the American Academy of Forensic Sciences. "That's the idea, anyway."
"In hanging, it's over really quickly," Young said.
The Physics of Hanging
Though it is arguably one of the oldest methods of execution still in use today, hanging is not a simple matter.
"The problem with hanging is that it is very difficult to calculate what it takes to do it well, to the extent that something like this can be done well," said Austin Sarat, professor of jurisprudence and political science at Amherst College in Massachusetts and an expert on judicial killing.
Forensic science suggests that Saddam's death occurred in one of two ways. The first of these, Lyle said, would have occurred if the noose snapped his neck, breaking a bone called the axis.
"If it's done right, what happens is that the weight of the body as it falls basically yanks the neck to one side," he said. "So the axis is either severely damaged or cuts the spinal cord."
"As soon as this happens, it's just like a guillotine."
Severing the spinal cord would have brought about a condition known as spinal shock. Lyle says spinal shock is the physiological equivalent of a total power outage.
"With a blackout, the lights all go out on a power grid," he said. "In the body, the blood vessels all relax almost immediately, and the blood pressure goes down to zero very quickly."
If the rope was too short, however, the speed of Saddam's fall may not have generated enough force to break his neck.
"In this situation, the rope cuts off two things," Lyle said. "The first are the arteries that supply blood to the brain, called the carotid arteries. The other is breathing."
Young said in this case, the lack of oxygen would start the cascade of events that would have led to Saddam's death.
"The major thing that happens here is that you cut off the air supply," Young said. "The loss of consciousness is very rapid. Then you will see some very rapid brain changes, probably including the brain herniating and swelling rapidly."
This leads to a process called "coning," in which part of the brain becomes lodged in the spinal column.
"From that you will see rapid swelling, which leads to respiratory changes," Young said.
The whole process, in this case, would lead to death in just a few minutes. However, Sarat said this possibility is definitely more painful than a broken neck.
"If the rope is not long enough, the person will struggle while they suffocate," he said. "From our understanding, that's quite excruciating."
Whether death comes in seconds or minutes, it is unlikely that Saddam would have maintained consciousness through much of the experience.
"When you get a very vigorous trauma happening like this, one of the body's reactions is unconsciousness," Young said. "I think the time of death could vary on all kinds of circumstances, but we're talking about a few minutes at most when it comes to judicial hanging, if it is set up properly."
"The most definite thing is that there is not likely to be sustained suffering."
In either of these first two scenarios, Saddam's heart would have likely continued to beat for up to 20 or 30 minutes after his brain ceased to function. Though Saddam would have been technically dead at this point, officials conducting the execution would have allowed his body to continue to hang until his heart ceased beating.
There is also a third possible scenario.
"If they drop him too far, his head pops off," Lyle said. "But I don't think that we have to worry about it going wrong. I have a feeling the Iraqis know what they are doing."
Is It Humane?
In addition to the current controversy over Saddam's death verdict in general, many debate the choice of hanging as the method of execution.
As of 2005, hanging was still a legal form of capital punishment in 58 countries, including the United States, according to statistics from Amnesty International. It is the sole method in 33 countries.
"Traditionally, hanging is thought to be one of the more -- if not the most -- gruesome methods of state execution," Sarat said. "It is also thought that to be hung is a special dishonor. Most people in this situation would choose to be shot."
Lyle said, however, that death by firing squad is probably associated with the most complications.
"They try and aim through the heart, but people have been shot through the heart and lived, for a while at least," he said.
Among the remaining choices of execution, which include the electric chair and lethal injection, Lyle said hanging confers the second-highest possibility of complications.
"Hanging, next to death by firing squad, is the one that could have the most defects," he said.
"Then again, this is Saddam, so who cares? At least they're not going to stone him."
But Sarat said that regardless of the method, there is no justification for judicial killing in a civilized society.
"I'm not sure there is any method of execution that passes the test of being anything other than barbaric," Sarat said.
"It is very possible that Americans will think that this is a person who deserves execution. But as for the choice of hanging as a method, I hope and expect it to be found by people around the world to be barbaric."