Sophomore Jose Ulloa smacks the small blue ball with his hand, launching it toward the brown concrete wall of the old Lodi High School gym. His brother, freshman Francisco Ulloa, dives to return it.
In a nearby court, senior Maria Barron is playing with one of her friends. She hits the ball straight up into the air where it lands on the roof. The group of students laugh as she goes to find another one.
What might seem like a fun diversion during Lodi High School's lunch break on Tuesdays and Fridays has actually turned into an opportunity for kids, some of whom are involved in gangs, to connect in a safe environment.
For the $4 it takes to buy two packs of handballs each week, gang specialist Ruben Y. Guardiola is creating trust, respect and understanding between members of Lodi's two major gangs, the Norteños and Sureños.
"I don't expect them to start throwing barbecues together, but they've got to get along," he said.
And it's working.
Before the balls started flying, fights were common during lunch breaks.
But there has not been one fight or referral when the students are playing handball, Vice Principal Jeff Palmquist said.
"Kids we've had problems with in the past fighting with enemies or rival groups are out here playing together. ... They are coming together in ways we don't always see them come together," he said.
Since handball has started, Barron said she has noticed there have been fewer fights at lunch. She said Guardiola requires the students to be respectful.
"This is different. This is a boundary where you can't do anything. You have to respect each other here, and it keeps the violence and fighting out," she said.
Guardiola works for Point Break Adolescent Center, a Stockton-based nonprofit, and is contracted through a grant Lodi High received.
He spends most of his time talking with students one-on-one and trying to see where they are struggling and how he can help them. As a former gang member, he uses his own personal experiences and those of his family and friends to get the students back on track.
"I tell them, 'You will get shot, killed or locked up,'" Guardiola said. "Those are the only three things that are going to happen if you are in a gang."
While working at the school, he noticed that the students had nothing to do during their lunch break.
"They were sitting in the hallways, doing nothing and giving each other dirty looks. I needed to find something for them to do, something to keep them busy," Guardiola said.
He asked three Sureños and three Norteños to come help him paint white lines for the handball courts on the ground behind Lodi High's old gym and then played a couple of games with them.
"A lot of these kids already are trying to make a change. They want to get something in life. I tell them, 'We get one chance in life. You get out what you put in,'" he said.
Guardiola shares his own story with the students. He never planned to get involved with a gang but his friends started to fall into it, he said.
After being in prison three times and spending more time in jail, the 44-year-old got out of gangs in his early 30s because he was tired of leaving his wife and children when he was locked up. He moved out of Stockton's east side, and tells his students that it is always a struggle to cut ties with former gang members.
"I don't go out anymore. It's easy to get in trouble in the streets," he said.
Now, he works for Point Break, where he holds anger management and substance abuse classes in Stockton. Guardiola works at four other high schools in the area besides Lodi High, doing one-on-one intervention.
The experience of being in a gang helps him connect with the at-risk students because he said they listen more when he talks to them.
"How are you going to turn around and take advice from someone who has never lived the life?" he said.
When the students play handball, Guardiola said they know what is expected. Since he started working at the school, he said lunches are much calmer, and there is not as much tension.
"They give each other mutual respect, they give me that respect and that's what it is all about," he said.
In Lodi, Guardiola said there needs to be more activities on the weekend and evenings to keep kids busy.
"A lot of the kids won't go to the park because they don't know what's creeping around the corner," he said.
Councilman Bob Johnson, Interim Parks, Recreation and Cultural Services Director Jeff Hood and Recreation Superintendent Mike Reese watched the students play handball on Tuesday and discussed ways to spread the sport throughout the city.
"It's so low budget — get some balls, a wall and go play," Johnson said.
Francisco Ulloa said he occasionally plays handball at Tokay High School in his free time. He said the addition of handball during school has stopped rival gang members from fighting at lunch, and that continues outside of school.
"After school, we don't start that much stuff anymore," he said.