Barksdale fit that profile, outreach workers said.

In the 1980s, he terrorized housing projects in West Baltimore as a high-profile heroin dealer. He has been shot more than 20 times, according to law enforcement officials, and claimed to be the inspiration for the Avon Barksdale character in "The Wire."

Barksdale had been working with Safe Streets in the city's Mondawmin neighborhood since July 2012, using his gravitas to intervene in disputes before they ended in shots fired. Delaino Johnson, a Safe Streets veteran who directs the Mondawmin branch, said Barksdale's efforts had "a hell of an impact.

"From my standpoint he did good work with us," Johnson said. "He had a large impact on reducing violence in our targeted area."

While Safe Streets is generally careful to keep its distance from police to avoid the appearance that information is being shared with law enforcement, a representative from the Baltimore Police Department has a vote in hiring decisions.

As part of the hiring process, police perform background checks on applicants and program leaders regularly scan databases for new charges against employees. Safe Streets declines to hire anyone with open criminal cases, according to the health department, and being charged with a felony or violent crime while on the job means suspension without pay.

Barksdale was fired when he did not show up for work after his arrest last week.

He was accused of having ties to the Black Guerrilla Family gang in a federal affidavit in 2010 — before he was hired at Safe Streets — but DEA spokesman Edward Marcinko said that information might not have been readily available to police. Barksdale denied any affiliation with the gang at the time.

Then last week, Barksdale was arrested by U.S. Marshals. The Drug Enforcement Administration alleges he is a senior member of the Black Guerrilla Family, which in a separate case has been accused of running a massive smuggling operation at the Baltimore City Detention Center.

Barksdale remains in federal custody and his attorney declined to comment.

Marcinko said there was no evidence that Barksdale used his Safe Streets job to further alleged heroin dealing.

Frederick H. Bealefeld III, the former Baltimore police commissioner, said that the charges are not surprising because Safe Streets relies on people at the fringes of criminality to be effective.

Some police officers who work the streets are skeptical about Safe Streets, he said, and the charges will confirm their views and "provide them ammunition and reason not to engage.

"But I think that would be a mistake," he said.

While he emphasized that charges against one employee should not be used to undermine the whole endeavor, he also called for careful evaluation and management of its workers.

"It would be hard to be a recovering alcoholic living over a bar," he said. "It's very very difficult work, there's no question. ... Somebody really kind of has to be watching your back and helping."

The DEA previously described links between the program and the Black Guerrilla Family, which police say drives much of the Baltimore's violent crime, in the 2010 case.

Two people who worked at a West Baltimore nonprofit that once had links to Safe Streets were charged with being major gang figures, and an affidavit filed as part of the case alleged that a separate East Baltimore Safe Streets site had been taken over by the gang.

Rawlings-Blake's task force searched for signs of Black Guerrilla Family infiltration, but the review found no evidence of a gang problem inside the program.

Despite the problems, Scott said the program's unusual approach is a valuable addition to traditional crime-fighting agencies as Baltimore continues to battle against violence.

"It can't just be about police, it can't just be about City Hall and it can't just be about the state's attorney's office," he said.

Baltimore Sun reporter Yvonne Wenger contributed to this article.