12, the new 21?

The summer toys were lazing about the asphalt backyard in Dorchester: baby pool, rocking horse, minicar.

But, police say, it wasn't child's play up in the top floor of the Fuller Street three-decker.

There, a 5-foot-8 130-pound male was helping run a marijuana operation from an apartment not his own, authorities say. They can't say much more: it's an ongoing case that landed in Dorchester District Court earlier this month .

But police records do say this: the reputed pusher they busted was 12 years old. City Weekly is withholding his identity because he's a juvenile.

As he unsuccessfully tried to flee the cops down the back stairs, the 12-year-old's footsteps were following a path that appears to be getting worn down -- young people committing serious crimes.

According to the most recent available Boston Police statistics, the number of youths 16 and younger arrested for drugs jumped 42 percent from 2004 to 2005.

During the same period, the number of juveniles collared on weapons violations, including guns and knives, slightly more than doubled. Overall, arrests of juveniles for violent crimes during that time swelled 14 percent.

The young upswing, police say, is a driving force behind the city's current crime convulsion -- and is driving would-be conciliators and others mad.

``Chaos" is how Leo Williams describes the current status of the Dorchester backstreets he ran as a young thug in the '90s.

Now 27 and volunteering his services to ministers as a youth mentor despite a drug case still hanging over his head, Williams has seen the age of innocence plummet. During his prime, he says, street players were in their teens and twenties. Today, he says, teenagers and 12-year-olds are becoming criminal role models for children 9 and 10 as the culture of violence continues to calcify in the community.

These days, Williams and others say, there are increasing numbers of hardened boys as young as 12 who toy with real guns as if they were made of Legos. Sixth- and seventh-grade girls who are schooled on how to become prostitutes by powerhouse pimp-daddies. Kids having kids before they reach high school.

``Superbabies," Williams calls this generation, weaned on technological advances and traumatic setbacks.

Raised in families divided by years of drugs and despair, they're often left to fend for themselves, he and others say. Too young to obtain working papers, they're savvy enough to find employment in the underground markets: slinging drugs, or stealing cars or jewelry.

From 2004 to 2005, the number of juveniles arrested for vehicle theft increased 30 percent; those nabbed in robberies spiked 54 percent.

A collision between a demographic rise in young people and a dramatic dip in government funding of head-'em-off-at-the-pass programs has created serious fallout.

According to a special report on youth violence presented by members of the City Council last month, the number of high-school-age kids in Boston this year reached its highest level in over a decade.

Meanwhile, the city since the early 2000s has lost $8.6 million in federal funding that had been targeted to prevent such young people from getting into trouble, the report says.

The fingerprints from the decline in dollars, activists say, are all over: From 2001 to 2005, the number of juveniles arrested for all types of crimes in the city bumped up 15 percent, according to the Boston Police Department.

With couples working overtime to make ends meet, even kids from solid families are being babysat by violent video games, violent TV shows, violent music -- and violent streets, says Chris Sumner , executive director of the Boston TenPoint Coalition, a faith-based group working with at-risk children.

``The culture of violence is the new after-school program," says Sumner.

The aggressive new class of villains includes young girls, who, youth workers say, swathe their faces with Vaseline to prevent their pouts from being scratched during their regular female-only fights.

Meanwhile, back at their old posts in the inner city after doing prison bits for their ' 90s crimes, some of the OGs -- Original Gangsters, as they are often called -- are more than willing to tutor the young ones in the ways of the streets, cops and community activists say.

The kids can earn street stripes and spending money by holding the drugs and guns for the older guys, who'd face harder prison time than the juveniles if they are the ones caught with the goods.

``They bring prison culture to the hotspot," says Emmett Folgert , director of the Dorchester Youth Collaborative, about the OGs. ``The little kids start walking around as if they're lifers. . . . They actually think they're Al Capone."

Part of their gangster gestalt is an anti-rat code.

The no- snitching mentality not only makes it harder to solve crimes, says Folgert, but also perpetuates new violence when young victims become perpetrators by taking justice into their own hands.

``You never forget the humiliation of being beaten down by the group," says Folgert. ``These kinds of humiliating beatdowns build and build in a neighborhood. Kids start fighting each other."

Though joining gangs at younger ages than in previous eras, activists say, today's youths -- including the 12-to-14-year-old so-called Baby Gs -- are entering for some of the same reasons: for money to buy basics and bling; for protection from their neighboring enemies; and for a feeling of closeness they don't find in their own families.

But some of the motives behind the beefing have changed.

In years past, many youths battled over drugs and turf and gang colors. Now, activists and cops say, young people -- whether affiliated with gangs or not -- can also tangle over everything from the settling of deep-seated scores to random dislike of somebody's clothing or hair or speaking style.

The randomness makes it harder for cops to figure out patterns of retaliation and prevent them.

Police officers say that although the adolescent terrain is tough, and resources tight, they are determined to turn things around, in part by focusing on the double edges of the crime continuum.

With potential young players, police will identify them by the known troublemakers they hang out with, and where.

Cops then join with clergy to enlist the help of parents to prevent their kids from joining the criminal life.

With incarcerated cons, a panel including law enforcers will let them know about possible housing and jobs to avoid the illegal rackets -- or the legal sanctions awaiting them if they insist on returning as streetcorner criminals and instructors.

``Even with all the challenges we're going through," says Boston Police Superintendent Paul Joyce , citing other crime cycles the cops have halted, ``I am optimistic we will move out of this."

For now, a check of the police blotter since April finds it peppered with young bloods: ``Juvenile arrested for shooting at Samuel Morse Way. . . . Juvenile arrested for ammunition possession. . . . 4 juveniles arrested after armed robbery. . . . Juvenile arrested on West Newton Street for firearms violations. . . . Juvenile arrest for possession of a firearm. . . . 14-year-old shot in Roxbury. . . . South Boston juvenile arrested for intimidation of a witness. . . . Juvenile stabbed while exiting bus."

Over the last seven or so years, says the Rev. Shaun Harrison , his outreach to youths has expanded its scope from those in high and middle school to include elementary-level children.

Harrison says he's currently trying to coax one Dorchester gang member to turn in his guns. He has two of them, Harrison says.

The boy is 12.

Earlier this month, Harrison says, he was in the boy's bedroom -- decorated red out of allegiance to his crew, the Bloods -- and delivered this message:

``I love you very much. If you go out and shoot somebody and you go away for life, I'm going to miss those times I shared with you, and a piece of me will die inside because you're not there anymore."

Harrison says the boy offered to give up his bullets. But, for now, he wanted to hang on to his weapons.

Harrison believes he'll get the guns out of the 12-year-old's hands, eventually. He'll keep trying.

``Twelve-year-olds," says Harrison. ``If we don't stop them, they will be the next 21."

Ric Kahn can be reached at rkahn@globe.com.