David Coleman Headley seemed like a gregarious, high-rolling American businessman when he set up shop in Mumbai in September 2006.
He opened the office of an immigration consulting firm. He partied at swank locales such as the ornate Taj Mahal Palace hotel, a 1903 landmark favoured by Westerners and the Indian elite. He joined an upscale gym, where he befriended a Bollywood actor. He roamed the city taking photos and shooting video.
But it was all a front. The tall, fast-talking Pakistani American with the slicked-back hair was a fierce extremist, a former drug dealer, a one-time Drug Enforcement Administration (DEA) informant for the United States who became a double agent. He had spent three years refining his clandestine skills in the terrorist training camps of the Lashkar-i-Taiba militant group. As Headley confessed in a guilty plea in a US federal court this year, he was in Mumbai to begin undercover reconnaissance for a sophisticated attack that would take two years to plan.
In 2006, US counterterrorism agencies still viewed Lashkar primarily as a threat to India. But Headley's mentor, Sajid Mir, had widened his sights to Western targets years earlier. Mir, a mysterious Lashkar chief with close ties to Pakistani security forces, had deployed operatives who had completed missions and attempted plots in Virginia, Europe and Australia before they were captured, according to investigators and court documents.
Now Mir's experience in international operations and his skills as a handler of Western recruits were about to pay off. Lashkar had chosen him as project manager of its most ambitious, highly choreographed strike to date.
Mir's ally in the plot was a man known to Headley only as Maj Iqbal, who investigators suspect was an officer of Pakistan's Inter-Services Intelligence Directorate (ISI) and a liaison to the Lashkar terrorist group. Iqbal is a common Pakistani last name, and investigators have not been able to fully identify him. Maj Iqbal and Mir worked as handlers for Headley, their lead scout, during his missions in India, according to investigators and court documents.
The iconic Taj Mahal Palace hotel was the centrepiece of the plan. When Headley returned to Pakistan after his first scouting trip, Mir told him he needed more images and also schedules for the hotel's conference rooms and ballroom, which often hosted high-powered events, according to investigators and court documents.
ProPublica, a US based, non-profit group of investigative reporters, has tracked the rise of Lashkar through Mir's career as a holy warrior. It is a story of a militant group that used political clout and support from Pakistani security forces to develop global reach and formidable tradecraft, according to investigators and court documents. It is also a story of how, despite warning signs, anti-terrorism agencies were caught off-guard when Lashkar escalated its war on the West with a 2008 attack on Mumbai that targeted Americans, Europeans and Jews as well as Indians.
As Mir and Headley plotted in 2006, French investigators were confronting the potential dimensions of the threat posed by Lashkar, a longtime al Qa'eda ally founded in the late 1980s and used by Pakistan as a proxy army in the fight against India for the Kashmir region.
France's top counterterrorism magistrate, Jean-Louis Bruguiere, had spent three years investigating Mir after one of his French operatives, Willie Brigitte, was arrested in a foiled bomb plot in Australia. Brigitte gave a long confession identifying Mir as his Lashkar handler, describing him as a figure whose influential connections made him "untouchable in Pakistan". With the help of foreign investigators, Mr Bruguiere built a case that Mir was a kingpin leading terrorist operations on four continents.
In October 2006, two years before the Mumbai attacks, Mr Bruguiere issued an arrest warrant for Mir that was circulated worldwide by Interpol. There was no response from Pakistan.
A Paris court convicted Mir in absentia and sentenced him to 10 years in prison in 2007. Nonetheless, Mr Bruguiere says most Western investigators he dealt with continued to view Lashkar as a regional actor confined to South Asia.
In 2007, Headley carried out two more reconnaissance missions.
Before and after each trip, he met with Mir and Maj Iqbal in Pakistani safe houses, turning over photos, videos and notes, according to investigators and US court documents. At one point, Mir showed Headley a plastic-foam model of the Taj hotel that had been built using the information Headley had gathered, according to investigators and documents.
Headley's work was complicated by a tangled personal life that got him in trouble again in December 2007. His estranged fourth wife, a Moroccan, told officials at the US Embassy in Islamabad that she believed he was a terrorist. She made references to training and suicide bombings and described his frequent travel to Mumbai, including her stays with him at the Taj hotel, US law enforcement officials say.
But US agents at the embassy decided the woman's account lacked specifics. Headley continued to roam free.
As the plot took shape in 2008, the FBI and CIA began hearing chatter about Lashkar. The agencies warned India at least three times about threats to Mumbai. The intelligence may have come from communications intercepts or sources in Pakistan. But privately, some US and Indian anti-terrorism officials express suspicion that US agencies were tracking Headley's movements and picking up bits and pieces about the plot without realising he was deeply involved.
US intelligence officials say they did not warn the Indians about Headley because they did not connect him to terrorism until months after the attacks. Although they say Headley was no longer working as a DEA informant by early 2008, it is not clear when that relationship ended or whether it evolved into intelligence-gathering. The CIA and the FBI say Headley never worked for them.
In April 2008, Headley's Moroccan wife returned to the embassy in Islamabad with another tip. She warned that her husband was on "a special mission".
She also linked him to a 2007 train bombing in India that had killed 68 people and that India and the US had blamed on Lashkar, US officials say. Authorities have not implicated Headley in that still-unsolved attack, however.
Headley returned to Mumbai on a fourth scouting mission in May. He went on boat tours, using a global positioning system device that Mir gave him to assess landing sites for an amphibious attack, court documents say. That same month, US agencies alerted India that intelligence suggested Lashkar was planning to attack the hotel and other sites frequented by foreigners and Americans, according to US and Indian anti-terrorism officials.
Mir and the other Pakistani masterminds decided on a raid in which fighters take hostages to inflict maximum chaos and casualties. Mir oversaw a veteran Lashkar trainer who prepared 32 recruits during months of drills in mountain camps and at the group's headquarters outside Lahore, according to investigators and court documents.
The plan called for fighters to infiltrate Mumbai by boat. Fifteen candidates were sent to Karachi for swimming and nautical instruction. But the youthful country boys had little experience with water. Some got seasick. Some ran away from swim training. Trainers had to bring in eight replacements.
In July, Headley began his final scouting trip. The plotters isolated the 10-man attack team in a safe house in Karachi in mid-September and outlined their mission, using videos, photos and maps.
The attack squad left Karachi at 8am on November 22.
The gunmen hijacked an Indian fishing trawler, killed the crew and sailed to about five miles off the shores of Mumbai. On the evening of November 26, the squad transferred to an 11-seat dinghy and landed in a slum where lights, phones and police were scarce.
Lashkar had set up a remote command post in a safe house or a hotel that US and Indian officials believe was in Lahore or Karachi. The room was stocked with computers, televisions, internet phones from a New Jersey company and satellite phones that were manned by Mir and five other handlers, according to US and Indian officials and a report prepared by Indian intelligence.
The assault began about 9.30pm. Two-man teams hit four of the targets within a half-hour. Despite the US warnings, Indian security forces were caught off guard. Indian intelligence officers frantically checked known phone numbers associated with Lashkar and were able to intercept and record nearly 300 calls. Mir's voice dominated the conversations, according to officials and documents.
Using the alias Wassi, Mir oversaw the assault on the Taj hotel where 32 people died. The handlers in Pakistan made the attack interactive, relaying reports about television coverage to the gunmen and even searching the internet for the name of a banker they had taken hostage. After killing 10 people at the historic Leopold Cafe, a second assault team joined the two gunmen at the Taj.
"They wanted to see the Taj Mahal burn," a senior US law enforcement official said. "It was all choreographed with the media in mind."
Mir chided a gunman who grew distracted by the luxuries of a suite, according to one intercepted call.
"We can't watch if there aren't any flames," said Mir, who was viewing the action on live television. "Where are they?"
"It's amazing," the gunman exclaimed. "The windows are huge. It's got two kitchens, a bath and a little shop."
"Start the fire, my brother," Mir insisted. "Start a proper fire, that's the important thing."
At the nearby Oberoi Hotel, two attackers hunted Americans and Britons. They stormed the restaurant and shot Sandeep "Sam" Jeswani, 43, an Indian-American customer relations director for a radiation therapy company in Wisconsin. At another table, they executed Alan Scherr, 58, and his daughter Naomi, 13. The former art professor from Virginia had taken his daughter on a spiritual pilgrimage to India.
The gunmen killed 33 people at the Oberoi, then took refuge in Room 1856. After one gunman was killed, Mir encouraged the other to go out in a blaze of glory.
"For your mission to end successfully, you must be killed," he said in one of the intercepted calls. "God is waiting for you in heaven. … fight bravely, and put your phone in your pocket, but leave it on. We like to know what's going on."
Another team rampaged through Mumbai's central train station, killing 58 and wounding 104. Their tactics reflected Lashkar's training. They avoided running, which is tiring and churns up emotions. They stayed within arm's length in a "buddy pair" combat formation.
In the running gunfights that followed, the chief of Mumbai's anti-terrorist unit was killed along with an attacker. The other gunman, a diminutive 21-year-old shooter with a fourth-grade education, was captured. The confession of the lone surviving attacker proved vital to the investigation.
The six-storey Jewish centre known as the Chabad House was attacked about an hour after the assault began.
Rabbi Gavriel Holtzberg, the 29-year-old director, and his pregnant wife, Rivka, 28, had entertained visitors in the second-floor dining room that night. Two rabbis from New York, Aryeh Leibish Teitelbaum and Ben-Zion Chroman, had stopped in to say goodbye as they wrapped up a trip to India to certify kosher food products.
When Holtzberg heard shots and screams, he grabbed his mobile phone and called a security officer at the Israeli consulate.
"The situation is bad," he said.
Then the line went dead.
The gunmen shot the Holtzbergs and the visiting rabbis. The Holtzbergs' son, two-year-old Moishele, wandered among corpses and debris until the next day, when his Indian nanny crept upstairs, grabbed him and escaped.
News that one of his men had been captured reached Mir in the command post.
He decided to try to win his release by using the two female hostages who were still alive at Chabad House: Yocheved Orpaz, an Israeli grandmother, and Norma Rabinovich, a Mexican tourist.
Mir told a gunman to hand Ms Rabinovich the phone. He ordered her to propose a prisoner exchange to Israeli diplomats. She reported back to him after her conversation with the Israelis, addressing him as "sir".
"They are calling the prime minister and the army in India from the embassy in Delhi," she said.
Mir's serene tone made him sound like a helpful bureaucrat.
"Don't worry then, ah, just sit back and relax and don't worry and just wait for them to make contact," he told her.
Hours later, Mir gave the order to kill her. A gunman named Akasha sounded reluctant. Mir turned icy. "Have you done the job or not?"
Akasha executed the women as Mir listened.
The next morning, helicopter-borne commandos swooped on to the roof. Mir gave real-time orders as he watched the gunfight on television. Akasha reported in a hoarse, strangled voice that he had been wounded in the arm and leg.
"God protect you," Mir said. "Did you manage to hit any of their guys?"
"We got one commando. Pray that God will accept my martyrdom."
"Praise God. Praise God. God keep you."
The three-day siege of Mumbai triggered international outrage.
The United Nations put Lashkar chiefs on a blacklist. Pakistan detained Hafiz Saeed, the group's founder, for another in a series of short-lived house arrests. Western authorities scrambled to re-assess the threat from Lashkar.
Unruffled, Mir and Headley were already at work on their next target: a Danish newspaper that in 2005 had published cartoons of the Prophet Mohammed. In November, Mir gave his scout a thumb drive with information about Denmark and the Jyllands Posten newspaper, according to documents and officials. They called the new plot "The Mickey Mouse Project".
In December, Mir met Headley again. Headley suggested narrowing the scope of the plot and killing only the cartoonist and an editor. Mir disagreed.
Despite the uproar over Mumbai, he seemed eager to take an audacious terrorism campaign into Europe, according to documents and investigators.
In January 2009, Headley travelled from Chicago to Denmark. Using his business cover, he visited the newspaper's offices and inquired about advertising his immigration firm. He shot video of the area and - because Mir mistakenly believed the editor was Jewish - of a nearby synagogue, documents say.
But a few weeks later, Mir put the plan on hold, according to documents and investigators. Pakistani authorities had finally arrested a big fish: Lashkar's military chief. They also arrested a Lashkar boss who had allegedly worked the phones with Mir at the command post for the Mumbai attacks.
In March, Mir sent Headley to India to scout more targets. But Headley was fixated on Denmark. For help, he turned to IIyas Kashmiri, an al Qa'eda boss. Kashmiri offered to provide Headley with militants in Europe for the attack. He envisioned attackers decapitating hostages and throwing heads out of the newspaper office windows, documents say.
Headley accepted the offer. Still, he kept urging Mir to return to the Mickey Mouse Project, according to documents and officials. In an e-mail in August, Headley described another reconnaissance trip to Copenhagen. He jokingly complimented Mir about his "music videos" - code for a TV programme about Mumbai that had featured Mir's voice directing the attacks.
Mir warned his operative to be careful, according to documents and officials.
"Your skin is dear to me, more than my own," Mir wrote.
In September 2009, documents show, Headley again discussed joining forces with Mir for the Denmark attack, a sign that Mir was operating freely. But Headley wasn't so lucky. His contact with two al Qa'eda suspects in Britain had put him on the radar of British intelligence, who alerted their US counterparts. In October, the FBI arrested Headley in Chicago, where he had a Pakistani wife and children.
The FBI had been working the Mumbai case ever since agents from Los Angeles rushed to India after the attacks. Their leads - phone analysis, forensics, money trails - had been instrumental to the Indian and Pakistani investigations.
Headley's co-operation gave the FBI a treasure trove of evidence and intelligence.
In March he pleaded guilty to helping organise the Mumbai attacks and the Denmark plot. His confession and the contents of his computer showed he had scouted scores of targets, including American ones, around the world, officials say. Investigators say he did not do reconnaissance in the US, but they noted a chilling detail: his immigration consulting firm had offices in the Empire State Building.
The ProPublica reporter Sharona Coutts and researchers Lisa Schwartz and Nicholas Kusnetz contributed to this report. ProPublica is an independent, nonprofit newsroom that produces investigative journalism. ProPublica is supported entirely by philanthropy and provides the articles it produces, free, both through its website, propublica.org, and through other news organisations.