Ali Hasan Al-Majid was No. 5 on the list of Most Wanted Iraqis and the king of spades in the so-called "deck of cards." A cousin of Saddam's, he earned his nickname for gassing Kurdish villages in the eighties.
The CBS News Early Show reported that al-Majid had been caught inside Iraq.
At an afternoon briefing at the Pentagon, Central Command head Gen. John Abizaid refused to discuss details of the operation because, "it would give away things we do not want to give away."
Just two days earlier, Taha Yassin Ramadan, who served as vice president under Saddam, was handed over to U.S. forces in Mosul on Tuesday, the U.S. Defense Department said. He was 20th on the Most Wanted list.
On April 7, al-Majid was believed killed by a British airstrike on his house in Basra, but signs soon emerged that he was still alive.
General Richard Myers told reporters in June that interrogations of Iraqi prisoners indicated he had survived.
Asked Thursday if Chemical Ali was behind recent attacks in Iraq, Abizaid said al-Majid appeared to have been playing some distant role in the insurgency.
"Chemical Ali has been active in some ways in influencing people around him in a regional way," he said.
Believed to be in his fifties, al-Majid led a 1988 campaign against rebellious Kurds in northern Iraq in which whole villages were wiped out. An estimated 100,000 Kurds, mostly civilians, were killed.
In an interview with CBS Radio News, former U.S. Ambassador Peter Galbraith described al-Majid as "almost the Josef Mengele of this operation. It was a deadly experiment to see which of these weapons were the most effective." Mengele was a notorious Nazi doctor.
Al-Majid also has been linked to the bloody crackdown on Shiites in southern Iraq after their uprising following the 1991 Gulf War. Prior to that, he served as governor of Kuwait during Iraq's seven-month occupation of its neighbor in 1990-1991 — an invasion that led to the Gulf War.
"The hills of Kurdistan bear witness to his cruelty. The southern part of the country where he put down the rebellion in 1991 bears witness to his cruelty," said CBS News Mideast consultant Fouad Ajami.
Human rights groups had called for al-Majid's arrest on war crimes charges when he toured Arab capitals last January seeking to rally support against mounting U.S. pressure on Saddam's regime.
"Al-Majid is Saddam Hussein's hatchet man," Kenneth Roth, head of Human Rights Watch in New York, said at the time. "He has been involved in some of Iraq's worst crimes, including genocide and crimes against humanity."
Hazem al-Youssefi, Cairo representative of the opposition Patriotic Union of Kurdistan, described al-Majid as a standout in a regime of criminals.
Al-Majid was a warrant officer and motorcycle messenger in the army before Saddam's Baath party led a coup in 1968. He was promoted to general and served as defense minister from 1991-95, as well as a regional party leader.
In 1988, as the 1980-88 Iran-Iraq war was winding down, he commanded a scorched-earth campaign to wipe out a Kurdish rebellion in northern Iraq. Later, he boasted about the attacks, including the March 16, 1988, poison gas strike on the village of Halabja, where an estimated 5,000 people died.
During April 1991 peace talks in Baghdad, the Kurdish delegation leader, Jalal Talabani, told al-Majid that more than 200,000 Kurds lost their lives in the Iraqi campaign. Al-Majid replied that the figure was exaggerated and the dead were not more than 100,000, according to Arab press reports.
After Iraq's 1991 Shiite Muslim uprising was crushed, Iraqi opposition groups released a video they said had been smuggled out of southern Iraq. In the video, which was shown on several Arab TV networks, al-Majid was seen executing captured rebels with pistol shots to the head and kicking others in the face as they sat on the ground.
He was no less brutal with his own family.
His nephew and Saddam's son-in-law, Lt. Gen. Hussein Kamel, was in charge for many years of Iraq's clandestine weapons programs before defecting in 1995 to Jordan with his brother, Saddam Kamel, who was married to Saddam's other daughter.
Both brothers were lured back to Iraq in February 1996 and killed on their uncle's orders, together with several other family members.
Syria and Lebanon ignored international calls to arrest al-Majid when he visited in January. He dropped scheduled stops in Jordan and Egypt — both U.S. allies. Egypt refused to receive him and the Jordanian government denied a visit was ever planned.
Al-Majid is one of the regime leaders who would likely be tried for war crimes, according to press accounts of a U.S.-drafted list of which commanders would face tribunals.