He may not have been a household name, but he has had a dramatic impact on Philadelphia's drug underworld.

For more than three decades, he was the quiet strategist behind taking down hundreds of the city's most violent drug traffickers and taking hundreds of kilos of drugs off the street.

His name: Henry James "Jim" Sweeney, 58, an FBI agent and supervisor who retired recently after 39 1/2 years with America's top law-enforcement agency.

One drug informant calls him "Jesus," because he believes that Sweeney could do no wrong.

"He's a walking encyclopedia of drug gangs in the region," said Jerry Daly, former police inspector of narcotics and now director of the Philadelphia-Camden High Intensity Drug Trafficking Area program, which funds drug-enforcement efforts in the area.

"He's a hard-charging guy, who backed his agents to the hilt," said Assistant U.S. Attorney David Troyer, who prosecutes violent drug cases.

Named in 1986 as supervisor of the FBI's first drug squad, known as Squad Two, Sweeney was not constrained by past practices in investigating violent drug traffickers, for which the squad became known.

"The FBI was new in drugs and didn't know how to make cases," said Sweeney, referring to the FBI obtaining jurisdiction to investigate drugs in 1982.

From '81-'82, Sweeney, Chuck Compton, now a retired Drug Enforcement Administration agent, and then-federal prosecutor Robert E. Welsh Jr. found a creative way to charge traffickers in a groundbreaking case.

At the time, the DEA focused on buy-busts and quick arrests, but the two agents used then-cutting edge techniques, including wiretaps, undercover purchases and consensual recordings under the then-new Racketeering Influenced Corrupt Organizations (RICO) statute.

"Sweeney and Compton brought the FBI into the modern world" regarding drug prosecutions, Welsh said.

Stunned Black Mafia leaders Lonnie Dawson and William Roy Hoskins were charged with attempting to kill a federal informant and drug offenses linked to the mob using RICO.

The RICO probe was such a big deal that former new York City mayor Rudy Giuliani, while associate attorney general in the Reagan administration, came to Philadelphia to announce the arrests, which later resulted in 125-year sentences for both Dawson and Hoskins.

Sweeney, a Baltimore native, was recruited in high school in 1970 to join the FBI's support staff. He also graduated from the University of Baltimore and served six years in the Maryland Army National Guard.

As a new agent in October 1976, Sweeney was assigned to work in Philadelphia - and never left.

Wearing a body-wire undercover, Sweeney foiled a jailbreak by a foreign spy, and sold phony drugs during the celebrated 1978-1982 case involving Ronald Raiton.

Raiton was the largest East Coast importer of phenyl-2-propanone, a precursor chemical for making methamphetamine, which was sold to the Nicodemo "Little Nicky" Scarfo mob, among others.

Once he discovered violent drug traffickers here, Sweeney found his mission in life.

"For me, locking up leaders of organized crime did not have the same satisfaction as locking up drug gangs," he said.

"Drugs tear neighborhoods apart. Kids have no life, no future, other than jail. People look to see who has the money, and it's the drug dealer, over and over again."

As police inspector, Daly said, he and Sweeney "bumped heads" about sharing drug intelligence. But Sweeney said that the FBI is prohibited by law from sharing information obtained from court-authorized wiretaps until trial.

Sweeney was "creative and aggressive," a supervisor who took "unconventional approaches to making cases, often to great results," said David Fritchey, chief of the U.S. Organized Crime Strike Force.

Retired FBI agent Jesse Coleman, Sweeney's onetime partner and a prolific investigator, credited him with inventing "an investigative technique that hadn't been used before."

"You'd have a wiretap on a dealer and find out a drug shipment's coming," Coleman said. "You'd make a car stop, and see the guns, money and drugs inside. You'd take it off them, and let them go. They were shocked.

"They'd get right on the phone and tell what just happened," he explained. "We'd get more wiretaps on these guys, and they'd chatter more on the tapes and include more people in the conspiracy."

If an officer or a lawyer asked why they weren't charged, Coleman said, "They'd be told: 'Guess what? There's a problem with the warrant.' "

"It was so shocking in law enforcement that we would take that chance," he added. "Instead of arresting three guys, we'd arrest 10 or more."

Such tactics were used on "The Family" of the late drug kingpin Roland Bartlett; on George Martorano's international drug operation, Pizza Connection II; on the Junior Black Mafia; and even on imam Shamsud-din Ali, whose conversation on a drug wiretap led to a wide-ranging City Hall corruption probe in recent years.

Sweeney maintained a cadre of informants, even as a supervisor, and could rattle off the genealogy of drug dealers' extended families.

He urged agents - and later cops and state troopers who were cross-deputized as federal agents on the violent-traffickers' project - to get to know a dealer's personality, the way he thinks, his family, friends and associates.

Using this information, Sweeney created an environment to brainstorm how to catch them. These sessions prompted unconventional methods, such as when FBI agent Kevin Lewis installed a wiretap near the prison toilet of the vicious defendant Kaboni Savage, who uttered death threats into a flushing toilet in his cell at the Federal Detention Center. His threats could be heard through the plumbing system.

Savage's recorded threats to kill dealers' children, prison guards and informants - on the so-called "Toilet Tapes" - led to his conviction and a 30-year prison sentence.

When Coleman worked undercover with Sicilian heroin dealers in Delaware, Sweeney prepped him: "You say this. They'll say that. You say this. They'll say that."

"He had the whole conversation figured out, and it went down just like he said," Coleman said.

Sweeney also could motivate investigators.

"He knew how to push my buttons," Coleman said. "He'd never give me credit for my last case.

"He believed in driving you as hard as you can [go]," he added, speaking on behalf of himself and other investigators.

Sweeney never wanted to work at FBI headquarters in Washington, but he served a one-year stint after 9/11 as acting assistant special agent-in-charge here.

He loved the street, participating in surveillances, taking down drug dealers, making on-the-spot decisions.

He even engaged in firefights, such as a 1990 shootout with Dominican drug dealers at the Red Roof Inn, in Bensalem, and a 1994 firefight at Broad Street and Hunting Park Avenue, in which two agents were wounded and Sweeney shot three gunmen, killing one.

His squad arrived seconds after undercover agent Chuck Reed was fatally shot on Penn's Landing. His team uncovered - and foiled - a plot by South Philly drug dealer Louis Turra to kill mobster Joey Merlino.

"He was never looking for individual credit," said former special agent-in-charge Bob Reutter of the Philadelphia Division from '91 to '98. "He was confident enough to let the credit go to the case agents. But he'd be banging on my door for things he knew he could get.

"He will be missed, more than people can imagine," said Reutter.

Leaving the FBI was one of the most difficult days of his life, even though he had received a one-year extension of the mandatory retirement age of 57.

"He wanted to stay there and fight the drug war every day," Coleman said.