Using an annual three-day summit on transnational gangs as the backdrop, the Los Angeles Police and Los Angeles County Sheriff's departments signed an agreement to launch an officer exchange program with El Salvador, saying they and federal officials are increasingly turning to their foreign counterparts to hunt down Mara Salvatrucha (MS-13), 18th Street and other street gangs.

The homegrown L.A. gangs - both with strongholds in the San Fernando Valley - have ravaged Central American communities as thousands of immigrants returned to their homeland over the past two decades and spread a culture of violence.

"No single nation can fight gangs alone," said John Pistole, an FBI deputy director. "They are far-reaching criminal enterprises that ... often transcend state and international borders to accomplish their needs."

The one-time, 30-day exchange program will provide four Salvadoran officers and two police from each local agency the chance to swap surveillance tactics, fingerprints, files and investigative techniques.

But officials say the program is one of several, including the summit, that have helped them track gang members operating transnationally, most often in Mexico and Central America.

In December 2004, the FBI launched an MS-13 National Gang Task Force focused on dismantling the 10,000-member gang formed in the 1980s by Salvadoran immigrants trying to protect themselves on Los Angeles streets.

They say the program has helped them solve crimes from Miami to Los Angeles to San Salvador. Riding on early successes, the FBI and Salvadoran law enforcement officials last year opened a transnational anti-gang center in El Salvador.

An estimated 10 to 15 percent of L.A.'s 40,000 gang members have international ties, said LAPD Cmdr. David Doan.
And though they are only a fraction of the gangs, their crimes are especially disturbing.
Over the years, he has watched the problem grow as Los Angeles gang members extort residents by using their counterparts in El Salvador to carry out beatings of their family members.

"To deal with global crime we have to have a global response," LAPD Chief William Bratton said.
Last year's declining gang violence has been eclipsed over the past two weeks with several high-profile cases, including a shootout between Avenues gang members in Northeast Los Angeles and the wounding of eight people at a South L.A. bus stop.

Bratton noted that mounting an international response could help combat a gang problem that "is pernicious and ... has the ability to flare up very quickly."