Editor's Note: CNN Presents will broadcast a look at James "Whitey" Bulger, his past life and details about his life on the run as part of a special broadcast Sunday night, July 17, at 8 p.m.
Boston (CNN) -- James "Whitey" Bulger was raised in a tight-knit world of Irish families in a community that protected its own.
There were three boys in one room, six girls in another. As he grew up, authorities say, it wasn't long before he became one of Boston's most notorious gangsters.
He learned to fight and survive on the mean streets of South Boston -- "Southie" to residents -- and to local kids who wanted to emulate him, he was iconic.
"The guy was legendary," said John Shea, a former drug runner for Bulger who served 12 years in prison for cocaine trafficking. "He was legendary of being the guy that controlled everything that ever happened in South Boston and for the Irish Mafia. He made tough guys shake."
But for the past 15 years, authorities said the man feared across Southie lived a quiet, reclusive life in a small Southern California apartment. Before his arrest in June, Bulger and longtime girlfriend Catherine Greig passed themselves off as "Charlie and Carol Gasko" to their neighbors in the Los Angeles suburb of Santa Monica.
During that time, the fugitive Bulger became "the Elvis of gangsters," as one former FBI official put it, even as his escape from a pending indictment led to a scandal that tarnished the bureau.
Bulger has pleaded not guilty to 19 counts of murder, while Greig is charged with harboring a fugitive.
By the time the two met, Bulger had served 10 years for bank robbery in federal prisons -- first in Alcatraz, then Leavenworth. After getting out, he vowed he would never go back to jail.
When Boston Globe reporters Dick Lehr and Gerard O'Neill began their groundbreaking reporting on Bulger in the 1980s, they discovered a single, compelling fact.
"He hadn't gotten so much as a parking ticket since he was released," Lehr said. Bulger's lack of a record after 1965 was all the more startling, since Lehr and O'Neill found he was being investigated by Boston police and the Massachusetts State Police after a series of killings he was suspected of carrying out himself or ordering others to commit.
There was a reason Bulger was able to remain untouched: He was a confidential informant for the FBI, a federal judge later concluded in a 600-plus-page report in 1999. More than that, the agent closest to Bulger, John Connolly, routinely informed Bulger about ongoing investigations, federal documents later showed.
Lehr said Connolly "did everything, including breaking all kinds of laws over the years to keep that alive."
Connolly, now serving a 40-year prison term, did Bulger one final favor in the mid-1990s. He told him of pending indictments for drug and racketeering charges brought by agencies outside the FBI, and Bulger fled. He was on the FBI's Most Wanted List for more than 15 years, second only to al Qaeda leader Osama bin Laden as the bureau's priority.
Former FBI Agent Tom Fuentes, now a CNN consultant, says the bureau received more than 12,000 tips over the years about Bulger and where he might have been seen. In one case, Fuentes said, agents received a tip that Bulger would be on flight to an unknown city in South America.
"There were thousands of police officers involved in that round-the-clock operation," Fuentes said "Everyone went full bore to follow up on those leads and try to find him. In a way, he became the Elvis of gangsters."
But all along, it seems, Bulger and Greig were in Santa Monica, in a small apartment four blocks from the Pacific Ocean beaches, according to their building manager.
One neighbor, 88-year-old Catalina Schlank, told CNN she saw the couple she knew as the Gaskos regularly. They were friendly, she says, but cautious about giving away too much information.
"We were good neighbors, and we met mostly in the lobby picking up the mail," Schlank said. In one encounter, "I said, 'I don't see your husband coming and going with you.' 'No,' she said, 'He has depression. He doesn't sleep at night and starts sleeping at five in the morning.' And then it seemed he was better."
On one occasion, she asked the couple to be a point of contact in the case of emergency. They refused. The couple did not have a car, paid for everything in cash and had a phone number that went directly to an answering service, Schlank said. "I asked her, 'Can you give me your phone so I can call you?' So she gave me a number, but that number goes to an answering service," she said. "They take the message and they relay it to Mr. Gasko. And if they wanted, they would answer. If they didn't, you wouldn't get an answer."
Ultimately, the FBI began airing a public service announcement with an emphasis on Greig. Less than two days later, a tip generated because of that television campaign led to the couple's arrest in Santa Monica.
Inside, prosecutors said they found more than $800,000 in cash and 30 weapons, including handguns, an automatic rifle and a hand grenade.