Schools in the Washington district decided to install metal detectors in 1991 after one pupils stabbed another one.
No other school system in the region has embraced the technology, even as metal detectors have multiplied in courthouses, museums and other public buildings across the region over the past two decades.
Many school officials view metal detectors as costly, impractical and fallible. To suburban parents, they conjure up images of armed camps.
Other safety measures have proliferated in this decade, an initiative fed by fears of terrorism, the 2002 sniper attacks and several other school shootings. Security cameras, school-based police officers and locked entryways all are far more common now than a decade ago, according to the latest Justice Department findings on secondary school security, released in 2007.
Metal detectors appeared in urban high schools in the 1980s as a response to rising gang violence. The devices were common in New York, Detroit and other large cities when the D.C. school board embraced them 17 years ago, after a pair of stabbings at middle schools. Now they are in every D.C. middle and high school, along with X-ray machines, added in 1998 to scan book bags, coats and purses.
D.C. school officials say the detectors are a proven deterrent. They note that no firearm has been discovered inside a District school this academic year.
The trend toward metal detectors never spread much beyond a core group of urban schools, however. Nationwide, the share of secondary school students who walk through metal detectors at school has increased only slightly, from 9 percent in 1999 to 11 percent in 2005, according to the Justice Department.
The argument against metal detectors in schools starts with the bottleneck they can create at the front entrance, which might have to accommodate 2,000 students in 15 minutes. Then there’s the matter of staffing the machine over the course of the school day.
Suburban school officials are quick to point out that metal detectors have not completely stemmed the flow of weapons into D.C. schools. In February 2004, James Richardson, 17, was shot and killed near the cafeteria of Ballou Senior High School, a campus equipped with both metal detectors and X-ray machines. The shooter sneaked the gun in through a side door.
Metal detectors have yielded both success and failure. In February 2004, a D.C. police officer caught two students who were trying to sneak guns into Wilson High School after they were seen conspicuously avoiding the metal detector. But in September 2003, twin brothers were arrested only after they had brought a loaded handgun into the Dunbar High School cafeteria, apparently smuggling it in through a side door.
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