BAGHDAD – Jill Carroll’s captors appear to be involved in some of the most high-profile kidnappings of Westerners in Iraq during the past two years.

A Monitor investigation – including interviews with other kidnap victims, U.S., Iraqi, and Italian investigators, as well as court testimony in Iraq – ties her abductors, or others close to them, to at least five kidnapping incidents, including Carroll:

. The Oct. 19, 2004, abduction and subsequent murder of Irish aid worker Margaret Hassan.

. The abduction of French journalist Florence Aubenas on Jan. 5, 2005.

. The abduction of Italian journalist Giuliana Sgrena on Feb. 4, 2005.

. The Nov. 26, 2005, abduction of four members of the Christian Peacemakers Team and the subsequent murder of American Tom Fox.

While the investigation yielded corroboration of key details, it couldn’t conclusively prove that the leader of the ring that kidnapped Carroll also orchestrated the other four abductions. Iraq’s insurgent groups operate in small cells. They often collaborate on the basis of overlapping interests, family and tribal ties, but don’t have the direct command and control of a regular army.

Evan Kohlmann, a U.S. terrorism consultant, also notes that Iraqi insurgents typically use misdirection in their propaganda – sometimes disavowing attacks for which they are responsible, at other times claiming attacks in which they were not involved.

Still, the strongest evidence suggests that the same group that took Carroll also abducted Sgrena, the Italian journalist. In early March, Abu Rasha, the leader of one of the three cells handling Carroll’s kidnapping, went into great detail about Sgrena’s captivity. Since Carroll’s release, Sgrena has corroborated some of those details, although with some discrepancies.

For example, Abu Rasha told Carroll that Sgrena had shouted at them that they shouldn’t be kidnapping her when their stated goal was to attack soldiers and police, not journalists. In his version of that shouting match, Sgrena ultimately obeyed orders to be quiet and gave an apology.

In a phone interview from Rome, Sgrena confirms that she did yell at them just as Abu Rasha described. But she says she never apologized to her kidnappers.

Abu Rasha described Sgrena as “like a mother” to her captors and that because of that they didn’t harm her. Sgrena says she told them they shouldn’t harm her because she was old enough to be their mother.

Abu Rasha said they gave her a gold necklace shortly before her release, something Sgrena confirmed. Carroll also was given a gold necklace when she was released.

There were other similarities in how the captors behaved and treated the two Western women. Each was held in Iraqi homes, in dark rooms. Their captors pretended to be Shiite, when they were devout Sunnis. They encouraged the women to convert to Islam. In the final videos of Sgrena and Carroll, made just before their release, their captors ordered them to say they were well treated and voiced their support for journalists.

Though Carroll and Sgrena discussed the appearance and demeanor of their captors, neither could be certain whether the men were the same. Nevertheless, the many similarities in their experiences convinced Carroll that the same men were involved.

Sgrena and Hassan were the only hostages Carroll’s captors referred to by name, but they alluded to Aubenas and Fox.

On the third day of Carroll’s captivity, for example, Abu Nour, the leader of Carroll’s kidnappers, told her that he had also kidnapped a female French journalist almost exactly one year earlier. Aubenas was kidnapped Jan. 5, 2005, and held for more than five months.

Aubenas declined to give the Monitor details about her captivity, saying she had spoken enough at the time of her release and wants to put the experience behind her. The public descriptions she has given of her captivity are starkly different from the conditions under which Carroll was held. Aubenas was frequently bound and blindfolded in a basement, while Sgrena’s and Carroll’s environment in captivity was generally less threatening.

But there is other evidence that ties Aubenas to Sgrena’s and Hassan’s abductions.

Aubenas was kidnapped after interviewing refugees at a tent camp for Sunni refugees from Fallujah on the grounds of the Mustafa Mosque on the Baghdad University campus. A month later, on Feb. 4, 2005, Sgrena was taken from the same location.

Proximity alone wouldn’t be enough to link the two. But U.S., Iraqi and Italian investigators say the man who ran that mosque, Sheikh Hussein al-Zubayi, is the prime suspect in the abductions of Sgrena, Aubenas and Hassan, the deceased director of Care International in Iraq.

Sheikh Zubayi is a wealthy Baghdad cleric. Until last year, he was also a member of the Muslim Scholars Association, a hard-line Sunni group that was involved in both successful and unsuccessful ransom negotiations for foreign hostages in 2004. He has been in hiding since shortly after the Sgrena kidnapping.

Iraqi police investigators and prosecutors, as well as the Italian government, say captured insurgents have told them Zubayi was involved in the Aubenas and Sgrena abductions, as well as with the kidnapping and murder of Hassan. Hassan was murdered near Fallujah in 2004 by her kidnappers, who were apparently angry over an ongoing U.S. offensive in Fallujah.

In early June, a minor figure in the Hassan kidnapping, Mustafa Salman al-Jibouri, was sentenced to life in prison by a Baghdad court. At his trial, Mr. Jibouri said that Zubayi gave him a bag containing Hassan’s purse and ID cards for safekeeping. Jibouri said in his defense that he didn’t know they were Hassan’s at the time.

Jibouri’s court statements, and an interview with the Iraqi prosecutor in the case, paint Zubayi’s role as that of a ruthless and mercurial individual, determined to squeeze as much propaganda value as possible out of his kidnapping operations.

Jibouri also said in court that Zubayi was involved in Aubenas’s and Sgrena’s kidnapping.

Italian and Iraqi intelligence also tie Zubayi to Sgrena. Just before her release in a Baghdad neighborhood, Sgrena’s captors’ last words to her were to “be careful: the Americans don’t want you to return to Italy alive,” according to “Friendly Fire,” Sgrena’s own book about her abduction.

Her captors also gave the same warning to Nicola Calipari, the Italian intelligence officer who negotiated her release, according to a Western intelligence official and an Iraqi investigator. The Italians rushed directly to the Baghdad airport. U.S. soldiers manning a checkpoint mistook the car for a suicide car bomb and opened fire, killing Mr. Calipari and wounding Sgrena.

Investigators say that Zubayi effectively orchestrated the shooting. He called a U.S. tip hot line shortly after Sgrena and Calipari drove off and said a car matching the description of their sedan, carrying a bomb, would soon be on the airport road, according to Jibouri’s court testimony. This also was confirmed by an Iraqi investigator contacted by the Monitor, and an Italian police report leaked to Corriere della Sera, an Italian newspaper.

The 42-page U.S. report on the shooting incident says an intelligence warning that both a black car and a white car were likely to be carrying bombs on the airport road at the time of the incident was passed to the soldiers who opened fire. Sgrena’s car, a Toyota Corolla, was white.

Carroll also was told by her captors at the time of her release that the U.S. military would try to kill her.

Iraqi investigators, who asked not to be identified, say Zubayi kidnapped women because they made for good propaganda videos and were seen as an opportunity to raise money for Sunni Arab fighters.

European and Iraqi officials say that multimillion-dollar ransoms were paid in both the Sgrena and Aubenas cases. In Hassan’s case, a $10 million ransom was sought by Abdel Salam al-Qubaisy, a senior leader of the Muslim Scholars Association, according to Italian police wiretaps, transcripts of which were leaked to Italy’s La Repubblica newspaper in January. Monitor editors and the Carroll family say they paid no money to secure her release.

What role, if any, Zubayi played in Carroll’s kidnapping isn’t known. He has been on the run from the authorities for more than a year.