Gangs in San Mateo County are employing technology, organizing better and recruiting members as young as 11 years old, according to law enforcement officials.

Web sites, surveillance technology and hierarchies that resemble corporate organization charts are allowing the approximately 45 gangs operating in the county to grow more sophisticated.

Meanwhile the influence from highly organized prison gangs has filtered down to the county’s jail and juvenile hall, said Tim Gatto of San Mateo County Probation Department’s Gang Intelligence Unit.

The troubling trends persist amid recent anti-gang victories. The county’s homicide rate dropped by half to 14 in 2007. The county’s two-year-old Gang Task Force, which puts 20 officers from multiple agencies on the streets, has arrested 1,118 alleged gang members and seized 198 weapons and more than 4,247 grams of drugs since its inception.

While the homicide rate has declined overall, the county still averages about 200 violent gang-related offenses each year, according to probation department statistics.

“Younger gang members appear more willing to use violence to settledisputes,” Gatto said.

Recently, police have received reports of gangs recruiting middle school students and others as young as 11 years old, Gatto said.

“In the last four to six months I’ve been getting calls from mid-county and south county saying high- school-aged kids were coming onto their campuses,” Gatto said.

Ravenswood School District Superintendent Maria De La Vega said some of the schools, which are in East Palo Alto and East Menlo Park, had teenage gang members coming onto campus to enlist the middle school students. The problem was eliminated long ago through increased watchfulness and a close relationship with police.

“We’re aware of the gang activities in the community and we often hear about it when they’re having some kind of confrontation. If we get any hint of anything, we alert the police,” she said.

“Cyber-banging” — challenging rival gang members and bragging about crimes online — is also on the rise, as is surveillance operations by gangs. In recent parole searches, probation officers have found sophisticated maps of rivals’ gathering spots and uncovered hidden video cameras on one gang member’s property, Gatto said.

Deputy District Attorney Joe Cannon, who prosecutes San Mateo County gang members, says he has also seen a surge in gun cases and in cases of youths charged as adults.

“The major hot spots in the county are eastern San Mateo, East Palo Alto, Redwood City, Daly City, and to a lesser extent, South San Francisco and San Bruno,” Cannon said.

tbarak@examiner.com