Correction: Earlier versions of this article misidentified the school that called 911 for two students who hyperventilated during a food fight. This version has been corrected.

One day in March, pranksters turned the cafeteria at Robert E. Lee High School in Fairfax County into a maelstrom of hurled milk cartons and leftover lunch.

Close to 100 teenagers joined the melee, flinging sandwiches and water bottles. Hundreds of others, caught in the crossfire, screamed and ran for the exits. A 17-year-old, eight months pregnant, was knocked to the ground.

During a similar eruption at Centreville High School weeks later, two students — recent immigrants who presumably had little experience with the modern American food fight — hyperventilated to such a degree that officials called 911.

 The episodes at Lee and Centreville were part of a rash of food fights this year that left a trail of garbage-strewn cafeterias and stymied principals at Fairfax high schools. Nearly every guilty student escaped unpunished, protected by chaos that made it almost impossible for school officials to figure out who did what.

Now, spurred by food-fight frustration, Fairfax’s 27 high school principals are banding together to ask for a powerful disciplinary and security tool, one the county School Board has long prohibited: indoor surveillance cameras.

“When you have a situation like that, you think you’re going to remember everything you saw, but you just can’t,” said Paul Wardinski, principal of West Springfield High. He said he caught only one of dozens of students responsible for a food fight in May. “If we had video, we would have gotten them.”

The principals made their request to the School Board last week, reigniting a frequent debate in Fairfax over how to protect students’ civil liberties while maintaining safe schools. The request could come to a vote as early as November.

The interest in school surveillance comes at a delicate time, after months of public wrangling over disciplinary practices that many parents said were overly harsh. The School Board overhauled its policies in June, scaling back the practice of forcing students in trouble to switch schools.

Skeptics say installing cameras would be a step backward — a new way to police students who are already weary of policing. The debate could factor into School Board elections this fall.

“It looks to me like all they want to do is catch kids being bad when they wouldn’t normally be able to do that,” said Michele Menapace, a parent and discipline-reform activist. “Kids who really want to commit a crime are going to find a way to do it.”

Surveillance of cafeterias, hallways and other interior spaces is commonplace in suburban schools across the United States, including in Montgomery, Prince George’s, Prince William and Loudoun counties.

Fairfax — the region’s largest school system, with more than 174,000 students — allows cameras on building exteriors and inside buses but has resisted indoor surveillance in the interest of protecting student privacy.

A few years ago, the school system experimented with using cameras to deter theft in cafeteria lunch lines. They proved ineffectual and were removed.

Views shift on board

But several board members say their feelings have begun to shift.

“Now you have sexting. You have YouTube. You have Facebook,” said Tessie Wilson (Braddock). “I don’t believe that kids have an expectation of themselves of privacy, because they’re putting so much out there for everybody to see.”

James L. Raney (At Large) remarked: “My bias is always to support the troops, and in this case to support the troop commanders — the principals. Students apparently cannot be trusted to have a safe and secure cafeteria environment.”

Fairfax officials estimate that installing cameras just in cafeterias would cost $8,000 per high school. Installing additional cameras in crowded common areas such as hallways, lobbies and stairwells would increase the total cost to $120,000 per school — or more than $3 million for all high schools, a significant investment after three years of painful budget cuts.

All but three of the 27 principals said they would be willing and able to use school funds — money from parking fees, vending machines and building rentals — to foot the bill.

They said that, beyond aiding investigations, cameras would help secure schools in the evening hours, when facilities are open to the community for classes and recreation. During the day, they said, cameras would make schools safer by deterring drug dealing, bullying, fighting and theft.

“This is just something I think would help change the behavior of students in the building,” said Nardos King, principal of Mount Vernon High. “Anybody who is being filmed on camera acts differently. It’s just human nature.”

Disciplinary infractions in Fairfax schools have decreased in the past five years, according to data from the Virginia Department of Education. But principals said the food fights were occurring in a new and unpredictable era of flash mobs organized via social media.

“At any given time, any school could experience an unfortunate event, and having a video record of that event would be useful, if not expected,” said Abe Jeffers, principal of Lee High.

He pointed out that surveillance cameras helped authorities nab a group of teens who robbed a Montgomery convenience store en masse this sum mer.

Range of penalties

Punishment for participating in a food fight could range from a warning to a recommendation for expulsion — with the latter applied to a student who threw something dangerous and was charged with assault. At West Springfield, Wardinski considered canceling the senior prom after the food fight but instead assigned students to a day of community service.

One afternoon this month at J.E.B. Stuart High School, senior Mayss Saadoon, 16, shrugged at the prospect of more surveillance. “They can already search your backpack at school. They can search your car and your locker,” she said after the dismissal bell sent students streaming outside into the sun.

But junior Evan Finley, 16, said cameras would be an “invasion of my privacy,” and his mother, Marilyn Finley, agreed. She said she supports having cameras outside schools. But inside? “I guess I get a little funny feeling about cameras inside,” she said. “I think it’s a little extreme.”

The number of schools using cameras has ballooned since the mass shooting at Colorado’s Columbine High School in 1999 intensified concern about school security, said Lynn Addington, an American University professor who studies crime and school violence.

More than three-quarters of public high schools use video surveillance, according to 2007 data published this year by the National Center for Education Statistics and Bureau of Justice Statistics.

But there is little evidence that cameras make schools safer or change student behavior, Addington said. “It isn’t something that has been studied that much,” she said.

Board members said they will seek public comment before preparing rules for placement and funding of cameras. Several members asked principals to evaluate whether the cameras are worth the cost in dollars and loss of privacy.

“I know how tough it is to keep order in a school, but I need something more than your guts and your anecdotes,” board member Martina A. Hone (At Large) said at Monday’s meeting. “I need some harder data and some harder measurements.”