Inside the locked gates of a county juvenile detention facility in Sylmar, all eyes are on Ernesto "Satan" Deras.

Before him are two dozen teenagers accused of violent crimes and facing the prospect of being tried as adults and sent to state prison.

Deras, a veteran of the violent street gang Mara Salvatrucha, speaks in a dry monotone, but his message settles in with an ominous weight: Give in to gang leaders or other criminals and you'll waste away in prison — or die at an early age.

Lean, with close-cropped hair and wearing a Dodgers T-shirt, Deras looks younger than his 36 years. He's a gang intervention counselor with Communities in Schools, a North Hills nonprofit group. It's a job that takes him to the Barry J. Nidorf Juvenile Hall on Thursday afternoons and beyond: to dark street corners to calm tensions after drive-by shootings, to gang meetings at local parks to broker truces, and to his Pentacostal church in Van Nuys, where he invites gang members trying to start a new life.

At a time when Mara Salvatrucha, or MS-13, has grown dramatically and captured the focus of government authorities across the U.S. and Central America, law enforcement officers, policy analysts and human rights activists agree that more programs like Deras' that emphasize intervention, education and training are needed to counter the scourge of gangs.

Stephen C. Johnson, a Central America expert who studies MS-13 at the conservative Heritage Foundation, recently warned Congress that police and immigration crackdowns alone won't stem the growth of a gang that has up to 50,000 members in six countries.

"We are going to have to encourage opportunity and social progress," Johnson said in an interview. "If we don't, we won't have enough jails."

Even the FBI, which has deployed about 100 agents on MS-13 investigations nationwide, is looking beyond criminal prosecutions. "Enforcement alone is not going to stop the root causes of this gang," said Robert Clifford, director of the bureau's MS-13 task force. "We've got to reduce the supply of kids."

Among other things, Clifford said, he plans to have agents refer new recruits and youngsters on the fringes of the gang to intervention and counseling programs. Otherwise, arrest or deportation may drive them deeper into the group. "All we're doing is restocking or repopulating the gang," he said.

In the Maryland suburbs of Washington, where MS-13 membership has surged in recent years, authorities initially responded with tough police tactics. Now, they are gearing up a series of anti-gang programs, including a youth center near the heart of MS-13 turf in Langley Park.

Glenn F. Ivey, the elected prosecutor in Prince George's County, said more needs to be done to counter heavy recruiting by MS-13. "There's been a big hole there that we're trying to fill," Ivey said.

Maryland and other states are looking to Los Angeles, which gave birth to MS-13 two decades ago and has seen sharp drops in gang violence since the early 1990s.

As with law enforcement efforts, it is difficult to measure the effectiveness of prevention and intervention programs. Some gang investigators are suspicious and believe that anti-gang workers become too cozy with street criminals.

But among the models the U.S. Justice Department cites as most promising are programs like Communities in Schools. The program is successful in part, authorities in the Los Angeles area say, because Deras and other former gang members are able to penetrate bonds of loyalty that make gangs difficult for outsiders to reach.

"They bring hope to these kids," said Ken Kondo, an L.A. County Probation Department spokesman. "They're making a tremendous impact here."

'I Loved War'

In the spartan dayroom at the Sylmar lockup, surrounded by teenage offenders — most with shaved heads, several with gang tattoos — Deras offers his own life as an object lesson in war, street violence and redemption.

After his father died of cancer when he was 7, his mother raised him on a coffee plantation near Santa Ana, one of El Salvador's largest cities, where she cleaned the owner's home. When civil war broke out in 1980, the area became a battleground between government forces and leftist insurgents.

Deras recalls admiring the government soldiers, who wore matching green, U.S.-issued uniforms and carried M-16 rifles. When he was kicked out of a Catholic school at 16 for fighting, he joined the army.