LOS ANGELES — ROBERT BOZART joined his first gang when he was 14 and, for seven years, participated in all the rituals of the culture: vandalism, drug-dealing, retaliatory violence.Now older and wiser, he has a new mission: to steer the next generation of youth away from the life that has marred so many of his brethren. Mr. Bozart is part of the latest grass-roots effort to stem the spiral of gang violence in the nation's second-largest city and restore a semblance of tranquillity to inner-city life. Organizers of this "movement" hope to draw broad neighborhood support - including from an unusual source: past gang members, or "OGs" (original gangsters), as they're called. "These are yesterday's gang members trying to prevent tomorrow's tragedy," says Steve Valdivia, executive director of Community Youth Gang Services, a county-backed agency that is working with the organizers. Although the thrust appears modest so far, no one in this city is discounting any effort to quell the violence that in some neighborhoods borders on civil war. Historically, gang activity in Los Angeles has run in cycles: It flared up for a time and then died down. But the latest wave has been unusually long and intense. Los Angeles County has set a record for gang-related homicides the past two years, and 1991 will likely reach new heights. More than 340 gang-connected murders have been recorded here so far this year - up from 309 during the same period a year ago. "We seem to keep building on levels of violence that were unacceptable 10 years ago," says Sgt. Robert Jackson of the Los Angeles Police Department's special gang unit. Groping for explanations for the upsurge, authorities cite a variety of factors: more lethal weaponry, pervasive drug dealing, family instability, joblessness, inadequate schooling, lax laws. "They need to get stricter on the punishment for 'gangbanging, says Phyllis McNeal, a parole agent here. Behind the homicide statistics lurk other disturbing trends: * Recruitment. Membership in gangs keeps growing. Authorities estimate there are now 100,000 youths in 950 gangs in the area - double what it was just five years ago. Community workers see old and new reasons for the rise - protection, power, peer pressure. "It is trendy to be in a gang," says Mr. Valdivia. "You even have Madison Avenue selling it." * Migration. Gang violence continues to surface in communities throughout the region, not just tough neighborhoods of South-Central and East Los Angeles. It is a growing problem in the counties of San Bernardino and Riverside, east of Los Angeles, where many city residents have fled to escape such woes. In Hollywood, a police task force was recently set up to control cruising by gang members. Long Beach is struggling to quell a war between Hispanic and Cambodian youths. * Scattered shot. Police say a growing number of innocent bystanders are being hit by gang gunfire. Hardly a weekend goes by without another unintended victim - often a small child - being hit by bullets from too familiar "drive-by" shootings. "There are more shots being fired, and 'gangbangers' seem to be more brazen in where they're shooting," says Lt. Michael Savidan of the Los Angeles County Sheriff's Department. Trying to fashion some sort of peace out of this anarchy is what the new grass-roots group, "Brothers and Sisters Unlimited," hopes to do. The organizers claim to have the backing of residents, community activists, and OGs from more than 100 gang neighborhoods. Although the group doesn't have a definitive strategy yet, they hope to attack the gang problem at its root through employment, education, and other initiatives. "It is time to sound the alarm," says Fred Williams, a community youth worker. "It makes no sense that Los Angeles is known as the gang capital of the world." Brothers and Sisters Unlimited wants funding from the city to attack the problem, though Los Angeles's pockets are empty. "We have the carpenters to rebuild," says Bobby Lavendar, a principal organizer and former gang leader. "All we're asking for is the tools." Robert Bozart has no illusions about how daunting the task will be. But he says: "If this saves one life, it's worth it."