In 1999, the year of the shootings at Columbine High School in Colorado, Heath E. Morrison was a middle school principal in Maryland, shocked by what he and his colleagues saw as a terrible but unique episode. "There was this intense desire not to overreact," said Mr. Morrison, who is now superintendent of the Charlotte-Mecklenburg school district in North Carolina.
Since then, Mr. Morrison has come to view schools as much more dangerous places. In the wake of the Newtown, Conn., shootings last week, he finds himself contemplating heightened measures to protect students, including increasing the number of security officers in schools who carry their own guns.
"We are a country that has too much violence and too many ways to have people hurt or killed and not enough access to mental health services," Mr. Morrison said. "So if there was an ability to put an armed security officer in every school, I would have to seriously consider it."
Charlotte-Mecklenburg already stations armed security guards at the district's 28 high schools, though not at its 88 elementary schools. Across the country, some 23,200 schools -- about one-third of all public schools -- had armed security staff in the 2009-10 school year, the most recent year for which data are available.
Now, in the wake of the massacre at Sandy Hook Elementary in Connecticut, school officials across the nation are reviewing security protocols, including lockdown drills and building entry procedures, but also whether to hire more armed guards.
These questions arise amid a broader political and societal debate about gun control. While some people view the prospect of bringing additional guns into schools as fueling a culture of violence, others say children need the protection.
On Sunday, a former education secretary, William J. Bennett, indicated on NBC's "Meet the Press" that he would support such measures. "I'm not so sure I wouldn't want one person in a school armed, ready for this kind of thing," said Mr. Bennett, who served under President Ronald Reagan.
With national sentiment starting to move in favor of stricter gun laws, Gov. Rick Snyder of Michigan vetoed a bill on Tuesday that state lawmakers had passed just a day before the shootings in Newtown, allowing registered gun owners to carry concealed weapons in schools. But also on Tuesday, a legislator in South Carolina introduced a similar bill that would allow school employees to carry guns in schools.
The question of whether to place trained security guards with guns in schools is left up to local districts. These officers are charged with protecting students not just from intruders but also from each other. They often conduct classes in preventing gang violence or bullying, as well as handle more prosaic tasks like issuing traffic tickets.
According to the Council of the Great City Schools, cities including Albuquerque, Baltimore, Dallas, Houston, Los Angeles, Miami and St. Louis have armed officers in schools, either contracting with local police forces or recruiting their own dedicated security staff. Other cities, including Boston and New York, place unarmed security officers in schools. Sandy Hook Elementary did not have a security guard on campus.
In Texas, the tiny, one-school Harrold Independent School District, about 150 miles northwest of Dallas, enacted a policy five years ago to allow teachers and administrators who have gun licenses and agree to additional training to carry concealed weapons in school.
After the mass shootings at Virginia Tech in 2007 and in an Amish community in Pennsylvania in 2006, David Thweatt, the Harrold superintendent, decided that since the school was too small to afford a security guard, its employees needed to be able to protect students on their own.
"I looked around for solutions, and the only solutions are to have some kind of defense," Mr. Thweatt said. He added that having several staff members with concealed weapons was more effective than one security guard.
While supporters of gun control oppose allowing teachers or school administrators to carry guns, some are sympathetic to schools that want trained, armed security officers, given the recurrence of mass shootings. "Until we get a handle on that," said Josh Horwitz, executive director of the Coalition to Stop Gun Violence, "I certainly understand school districts" wanting armed officers.
In Richland County, S.C., which includes Columbia and surrounding suburbs, the sheriff's office has placed what it calls school resource officers in every middle and high school in the county's three school districts. Among the elementary schools, one officer covers two schools. All are armed.
"If they're not armed, they're no different than a janitor with a broom or a teacher with a piece of chalk," said Leon Lott, sheriff of Richland County. "A bad guy is going to need to be confronted with someone who is on equal footing."
Mr. Lott added that the presence of these officers, whose salaries are shared by the sheriff's office and the school districts, was a deterrent to would-be violent offenders. "If someone drives by and sees a sheriff's car on campus, they are going to keep going because they'll think, 'I'm not going to be able to do what I want to do. There's going to be a cop there to stop me,' " he said.
Sharla Benson-Brown, an education consultant and mother of three children, one of whom attends a public middle school in Richland County, said she felt comfortable with an armed officer being at the school but was not sure he could prevent an episode like the tragedy at Sandy Hook. "With a school being so big, there's only so many places he can be at one time," she said.
Constrained school budgets are likely to prevent any mass hiring or arming of security officers. But even if districts could afford to hire more armed guards, education and safety experts say that might not be desirable, especially if it made schools feel more threatening to students.
Larry Johnson, executive director of school security for the Grand Rapids, Mich., district and president-elect of the National Association of School Safety and Law Enforcement Officials, said violence prevention should start with counseling and social work, not weapons. His office has the authority to arm school security officers but has decided against it.
"We think we should concentrate more on the heart than the hardware," Mr. Johnson said.
This article originally appeared in The New York Times.