He and Cpl. Bruce McPhillips, school liaison officer with the South San Francisco Police Department, met with the boys' parents and the school. The parents were shocked.
"They had been buying those clothes for their kids without knowing what they meant," explained McPhillips. The boys stayed out of trouble from then on.
The moral of the story is that education and parental involvement are key, said McPhillips. In an ideal world, "every parent and every student would be educated about gangs every year," he said.
That may be a tall order, but in a presentation to the City Council Wednesday night, McPhillips said the SSFPD had already made good progress in reducing gang violence, compared to many other cities in the county.
"We don't have drive-by shootings here. Over 80 percent of the gang activity consists of graffiti and property crimes," he said.
Gang violence is on the rise across San Mateo County, but South City police were prepared for it early on this year. They created a gang-suppression unit and use an elaborate database to track gang members on probation.
McPhillips trained his colleagues to recognize gang signs and colors: red for Norteos, blue for Sureos, the two gangs that have roots in cities all over the state. The officers enforce the 10 p.m. curfew for minors.
As ready as they are, the officers are still up against a gang network entrenched in the city since the early 1980s.
"Some of the kids are part of the second or third generation [in gangs," said McPhillips. And reaching out to their parents doesn't always help, because some are former gang members themselves, he said.
Still, many parents have no idea that their children, sometimes as young as 14, have joined a local gang.
"Some of them are good kids from good families," said McPhillips. "It's all fun and games until they start having to 'make their bones' commit assaults and vandalism."
Councilwoman Karyl Matsumoto worried that parents were not aware of or accountable for their children's actions.
"Do parents know they shouldn't let their children out of the house with gang colors?" she asked.
Councilman Pedro Gonzalez suggested that the city form a youth commission, so the people most at risk of being drawn into a gang have a part in suggesting ways to combat them.
He also made a plea to the people assembled in the council chamber and those watching the meeting on television: "Help us. Call the police with any information you have, he said.
Correspondent Julia Scott can be reached at 348-4340 or by e-mail at firstname.lastname@example.org.