Allegations that Pakistan's intelligence service was involved in the Mumbai terror attacks will be scrutinised in an American court case starting on Monday when the man who helped plan the 2008 strikes testifies against his alleged accomplice.
David Headley, a Pakistani-American businessman who has confessed to his involvement in the attacks, will be the star witness in the trial of Tahawwur Rana, his childhood friend, in Chicago.
Rana is charged with providing material support for terrorism in the assaults, which killed 166 people, as well as a plot in Denmark that was never carried out. Opening arguments in the case, based on the deaths of six Americans in Mumbai, will begin on Monday.
The case has drawn international attention because Headley's testimony is expected to reinforce allegations that Pakistan plays a double game in the fight against terrorism. Its success will depend largely on how the jury views Headley, 50, who is said to have juggled relationships with multiple wives, terrorist groups and intelligence agencies.
Headley is a former informant for the US Dr ug Enforcement Administration (DEA). He pleaded guilty last year to conducting reconnaissance for the Mumbai attacks and for the Danish plot. His confessions painted a devastating portrait of Pakistan's Inter-Services Intelligence Directorate (ISI) – he says ISI officers helped the Lashkar-e-Taiba (LeT) terrorist group plot the commando-style attacks on Mumbai.
Rana's defence will centre on the ISI links. His lawyers say Headley duped Rana into thinking he was helping an ISI espionage operation in India, then betrayed him to escape the death penalty. The defence will argue Rana had no idea Headley was plotting mass murder.
"They are using a whale to catch a minnow," said defence attorney Charles Swift, calling Headley "a master manipulator".
Prosecutors recently raised the political stakes by indicting a suspected ISI officer for the murders in Mumbai. The officer, identified only as Major Iqbal, allegedly oversaw Headley's scouting in India.
The decision to indict Iqbal was made at high levels in Washington, sending a signal from Barack Obama's administration, which had expressed frustration about Pakistan's reliability even before Osama bin Laden was found and killed in Abbottabad.
"I think [the indictment] shows the government believes Headley when he says his handler was an ISI officer," said James Kreindler, a former federal prosecutor who is suing the Pakistani spy agency in New York on behalf of the Mumbai victims and their families in a separate case.
"At some point in time there is not going to be any doubt whatsoever that the ISI coordinated the attack with Lashkar."The indictment does not mention the ISI, part of a calculated low-key approach, according to an Obama administration official who requested anonymity because of the pending trial. But the prosecutors are likely to address the allegations about the ISI, especially as the defence has emphasised them.
"The decision not to name the ISI does not reflect second thoughts about the evidence," the official said. "There are no second thoughts about the evidence."
The prosecution's case is based on a secretive international investigation by the FBI and about 30,000 pages of court documents, most of them classified. Headley's testimony is backed by corroborating evidence including other witnesses and communications intercepts. If there is strong evidence that the ISI helped kill Americans, it would inflict further damage on an endangered alliance with Pakistan into which Washington has poured billions of dollars.
Pakistani officials deny any links to terrorism and question Headley's credibility because of his past as a double agent and criminal.
The Pakistani major and five of the six other alleged leaders of the Mumbai attacks charged in Chicago remain at large. The FBI has photos of some of them, intercepts of their voices and emails, and information about their whereabouts, but Pakistani authorities have done little to pursue the fugitives, US officials say. Pakistan's prosecution of several Lashkar chiefs arrested in 2009, including one now under US indictment, has stalled.
Rana, a doctor by training, met Headley when they attended an elite military school in Pakistan. He is the lowest-ranking suspect and is said to have let Headley use his immigration consulting firm as a cover overseas.
In her first media interview, Rana's wife, Samraz, who also has a medical degree, said she met Headley in the 1990s after she emigrated to the US. Although he was a convicted heroin dealer and recovering addict, he charmed her conservative family, she said from their bungalow near Devon Avenue, the heart of Chicago's South Asian community.
The bespectacled 48-year-old mother of three teenagers smiled wearily as she recalled Headley's relationship with her children.
"He was like a gateway to American culture for us," she said. "He was like a second father for my kids. My kids would say, 'he's cool, this guy'. He was taking them to the movies, Chuck E Cheese, all this fun stuff … He talked to me like a brother. He knows what I liked. He knows what my husband liked. He knows what my children like … He has different faces."
Headley, formerly Daood Sayed Gilani, was born to a mother from a rich Philadelphia family and a father who was a renowned, politically influential Pakistani broadcaster. Headley told investigators that he had a distant Pakistani relative who was a former deputy director of the ISI and an army general, according to Indian and US officials. If that link is confirmed, it could help explain why the agency later recruited Headley and how he had access to senior officers and militant chiefs.
At 17, he returned to the United States, where he managed bars and owned a video rental store. Multilingual and gregarious, he has shown a con man's gift for winning over accomplices, investigators and romantic conquests.
"He was a tall, handsome guy," Samraz Rana said. "He was wearing very expensive clothes and, I mean, he was really impressive."
After a 1997 arrest for heroin smuggling, Headley became a prized DEA informant who targeted Pakistani traffickers.
Immediately after the 11 September 2001 attacks, the DEA directed him to collect intelligence on terrorists as well as drugs. That December, the US government ended his probation early and rushed him to Pakistan, where he began training in Lashkar terror camps weeks later, according to court documents and his associates.
Some federal officials say he remained an informant for at least three more years until 2005, but the DEA says he was deactivated in early 2002.
Between 2001 and 2008, federal authorities were warned six times by his wives and associates that he was involved in terrorism. None of the resulting inquiries yielded anything. The FBI and CIA say he never worked for them.
Headley's personal life has also been dramatic. He has four children, including a son named Osama with a Pakistani wife from an arranged marriage in 1999. But he has been married to three other women and several of those relationships overlapped.
At times, Headley has worn a full beard and traditional garb and expressed warlike beliefs, quoting the Qur'an, praising al-Qaida and declaring his hatred for India. But he has often gone clean-shaven and behaved like a high-rolling entrepreneur with a taste for champagne and luxury.
After he began training with Lashkar, he joked with his third wife, a New York makeup artist, that their pet dog could be a good "jihadi dog," according to a close associate. Hardcore extremists shun dogs because they see them as un-Islamic and unclean, making dog ownership a possible cover for terrorists.
When the DEA arrested Headley in 1987 and 1997, Rana put up his house as bond. When the Ranas ran into financial trouble in 2005, Headley came to the rescue with a loan of more than $60,000 (£37,000), Rana's wife said.
"We were like almost at the border of bankruptcy," she said. "So my husband he became more close to him. And he said: 'Oh, he is my true friend because he helped me at this time when I really need money'."
But Headley had traits that made her uneasy. She said her husband told her Headley had once used an elderly aunt to smuggle drugs on a flight overseas, hiding the package in her pocket without her knowledge.
In 2006, the ISI recruited Headley in Pakistan, according to his confession. In addition to Iqbal, his trainer and handler, he said he met ISI officers named Major Samir Ali, Lt Col Hamza and Col Shah. After specialised ISI training, he undertook two years of missions in India directed by Iqbal and Sajid Mir, a Lashkar chief who is the suspected project manager of the plot.
Mir's voice was caught on wiretaps overseeing the three-day slaughter in Mumbai by phone. Some US and European anti-terror officials believe Mir once belonged to the military or ISI; others say he only had close ties to the security forces.
Iqbal is said to have assigned Headley to gather military intelligence, giving him about $28,000 to establish an office of Rana's firm in Mumbai as a cover and for other expenses, the indictment says.
Samraz Rana insists her husband had no idea about the plot. The Ranas travelled to Mumbai, where she has family, days before the attack in November 2008.
"It's a zero per cent chance that my husband is involved in this thing," she said. "My relatives are there … I was there. My husband was there. We [could have been] killed in that attack."
The defence, however, will have to explain wiretaps in which Rana appears to praise the Mumbai masterminds. Evidence indicates he communicated with Iqbal and helped Headley maintain his cover in Denmark in January 2009 by sending an email to an advertising representative at the Jyllands Posten newspaper, which Lashkar targeted because it had published caricatures of the prophet Muhammad, according to the indictment.
Iqbal met Headley at least twice about the Denmark plot, expressing enthusiasm about attacking the newspaper, according to Headley's account. The officer cut off contact with Headley when Mir, the lead plotter, backed away from the operation in March 2009, documents say. But Headley continued meeting and communicating with Shah and Samir Ali as the Denmark plot was taken over by al-Qaida, according to officials and an Indian court document.
Shortly before the Mumbai attack, Headley had brought his Pakistani wife and children to Chicago. They lived with the Ranas for 20 days before moving into a nearby apartment.
"They become very close to my kids," Samraz Rana said. "And the wife was nice. And we have like sort of family relationship at that time … Dave was not here, he only sent his family. So we were taking care of his family."
During this period, documents show, Headley was spending most of his time in Pakistan, where he had a Moroccan wife. The Ranas paid rent for Headley's family as part of the strict conditions he had imposed for repaying the money he had loaned them, she said.
The FBI arrested Headley and Rana in
October 2009. A DEA agent who had handled Headley when he was a drug
informant was present when investigators brought Headley in, perhaps in a
strategy to induce co-operation. Headley quickly did what he had done
in the past: he changed sides and spent weeks detailing his role in the
Despite Headley's guilty plea, Samraz Rana finds it difficult to believe that her jovial family friend helped plan the carnage of Mumbai. She recalled an anecdote her husband told about their military school days, when Headley would avoid morning prayers.
"Dave, he knocks on all the doors of students and he says, 'Get up, get up, it's time for prayer'," she said. "And then when everybody gets up, he went to his room and went to sleep, you know. So he was laughing. He was like that."
Now, though, Samraz Rana sees Headley as a predator.
"He just thinks about himself," she said. "I think he [studies] human beings more as compared to the ordinary person. He can understand what [someone] likes and he changes himself according to that… Now I realise what intention he had."
This report is part of a ProPublica and PBS Frontline investigation. ProPublica is a nonprofit newsroom that produces investigative journalism