School Metal Detectors

* This page is being updated in Summer 2023 including with analysis of recent artificial intelligence (AI) weapons systems, although many of the implementation considerations with these new systems are the same as with conventional metal detectors.

Day-to-day use of metal detectors is the exception, not the rule, in the majority of U.S. schools.  However, they are used in some larger urban districts with a history of chronic weapons offenses. And metal detectors are often brought up by parents and the media after high-profile school violence incidents.

There are many implementation issues school officials must seriously consider in discussions about potential metal detector use. Likewise, if used, their capabilities, limitations and expectations must be presented fairly and in context to the school community.

Metal Detectors and School Safety

National School Safety and Security Services receives a number of inquiries about metal detectors and school safety, especially after high-profile school shootings or other incidents of school violence involving weapons.

Are metal detectors in school necessary? Are school metal detectors effective?  Should all schools have metal detectors to improve school safety?

School Security and Metal Detectors: Seeking a “Guarantee” of School Safety

The majority of schools in the United States do NOT use metal detectors on a day-to-day basis.  While there are no credible statistics on the exact number of schools using metal detectors, stationary metal detectors used on a daily basis are typically limited to large urban school districts with a chronic history of weapons-related offenses.  U.S. schools regularly using stationary metal detectors on a day-to-day basis are the exception, not the rule.

Following high-profile incidents of school violence, such as school shootings or stabbing incidents, it is not uncommon for some parents, the media and others in a school-community to call for metal detectors in response to such incidents.  Parents understandably want some type of “guarantee” that these types of high-profile incidents will not occur again.  Some falsely believe that metal detectors can provide that guarantee.

Moreover, there is no single strategy, or for that matter even a combination of strategies, that can provide 100% guarantee that there will not be a shooting or other act of violence at a school.

School officials must therefore exercise caution to avoid overreaction, knee-jerk reactions and/or the temptation to throw up security equipment after a high-profile incident primarily for the purpose of appeasing parents and relieving parental, community and media pressures.  Doing so may very well create a false sense of security that will backfire on school officials in the long haul.

Metal Detectors and Schools:  Philosophical Debates

Typically, the debate about metal detectors in schools boils down to advocates calling for metal detectors in an effort to, “Do everything we can possibly do to make schools safer.”   Opponents of metal detectors in schools frequently oppose them out of their belief that metal detectors will create a “prison-like” environment and thereby adversely implicate the climate of the school.  Opponents also point to the costs of the metal detector equipment.

Unfortunately, the debates often get “stuck” at this point without probing deeper into important implementation considerations.

School Metal Detector Implementation Considerations

Ken Trump, President of National School Safety and Security Services, advises school administrators to exercise caution in avoiding making knee-jerk reactions after high-profile incidents of school violence.  In particular, he notes that while he understands the normal parent reaction of wanting some physical, tangible ‘guarantee’ of greater security, such as metal detectors or cameras, Trump believes that the practicality of implementation issues must first be considered.  Regarding metal detectors in schools, Trump notes that:

  • Debates about metal detectors in schools must go beyond “philosophical” debates (“do everything we can” versus “we don’t want to create a prison-like climate”).  The discussion must first and foremost focus on implementation considerations, and the “return on investment” versus the implementation costs (both financial and other as described below) of properly implementing a school metal detector program.
  • Discussions about the “costs” of metal detectors must go beyond the initial cost of the equipment itself. What will be the additional costs to staff the personnel needed to operate the metal detectors?  What will be the costs for ongoing maintenance of the metal detectors?  What costs will be experienced in replacing the metal detectors over time?  Looking at the initial costs of the equipment alone is misleading. How can one not acknowledge that at some point, funding will be needed for maintenance and replacement in order to continue the proper operation of the metal detector program?
  • Metal detectors are sometimes looked at by some parents and media as a substantial step toward preventing weapons in schools.  But they need to keep in mind that if their schools do implement metal detectors at all schools, many students may still ride school buses.  Would school officials somehow provide for metal detection of students before they board each of their school buses on the way to school each morning?  (Answer: It is doubtful that any school district could accomplish this task even if it wanted to do so.)
  • School shootings and violence often occur outside of the school on school grounds.  How will the metal detectors be deployed to provide prevent weapons offenses on those areas prior to students entering school?  (Answer:  Again, it is doubtful that any school district could accomplish this task even if it wanted to do so.)
  • How much time will be required to get hundreds, and in many cases thousands, of students screened through the metal detectors and into their first classes on time without disrupting educational programs?
  • How many security professionals will be hired to operate the metal detectors at morning student arrivals? How many will be needed to continue to staff the metal detectors throughout the school day?  How many will be needed to staff the metal detectors during after-hours activities and evening events until the building is closed?
  • What type of training will be provided to employees operating the metal detectors?  In addition to orientation training on operating the metal detectors themselves, what type of specialized initial and ongoing training will be provided on recognizing concealed weapons, monitoring for methods that could be used to circumvent the detection systems, etc.?  (Note:  Security and law enforcement professionals operating metal detectors at airports, courthouses and other locations often receive periodic training updates on news trends, concealed weapons, etc.  A one-time orientation alone for school security officials and/or teachers and staff operating metal detectors would be questionable if ever challenged down the road in court.)
  • Will the school district’s security leaders conduct integrity inspections and tests to evaluate the effectiveness and proper operation of the metal detection program?  Will surprise inspections, “undercover” persons with concealed weapons testing the system, and other measures be employed?
  • Assuming a school decides to operate daily stationary metal detectors at its main entranceway, how will all other doors at the school be secured and staffed to prevent unauthorized entry during student arrival and processing through the main entrance metal detectors?
  • Will all ground-level windows be permanently secured at all times so no one can pass a weapon through an open window to someone who already passed metal detector screening and is in the building?  Would doing so even be allowed by local fire marshals?
  • Is the school willing to operate the metal detectors on a 24-hour/7-day-a-week basis?  Or, as has been done in some districts with metal detector programs, will the detectors only be used at the time of school opening and then shut down later in the morning, missing tardy students and others who come in the school later in the day?  Will all school employees also be subject to metal detector screening?  Will all parents and other visitors be screened on a regular basis?   Will the metal detectors be operated during all after-school activities, evening/night education programs, athletic and activities group practices, athletic events, plays and musical performances,  etc?  Will individuals participating in any and all community meetings and activities that are operated at the school be screened?  [Note:  The failure to run a 24/7 metal detection program creates an opportunity for persons to enter the school during non-detection operation times and store weapons in the building, if one would desire to do so.  As such, the perceived “guarantee’ of safety that some belief metal detectors would provide in schools is truly a false and misleading perception. They may serve as a risk-reduction tool, when properly deployed, but like any other single strategy cannot offer the ‘guarantee’ that some perceive them to provide.}

and numerous other considerations.

School Metal Detectors and Other Equipment Only as Strong as the Human Element Behind the Machines

Even a well-run school metal detector program is not 100% foolproof.  Any security technology is only as effective as the human element behind the equipment.  We know that the first and best line of defense against school violence is a well-trained, highly-alert school staff and student body, and that the most common way we find out about weapons in schools is when students report such information to adults they have relationships with and trust.

When security fails, it is because of people. When it succeeds, it is because of people.

While not anti-metal detector or anti-equipment, Ken Trump and colleagues at National School Safety and Security Services also know that schools are very, very unlikely to operate a 24/7 metal detector program and to take other measures as described above.  We also recognize it would require an enormous amount of financial, manpower and oversight resources to properly do so.  Thus we are pretty confident that there are numerous gaps and holes in implementation of school metal detector programs.

As we look at metal detector programs in the current day, it is interested to look back in prior decades as some of the same concerns and likelihoods of metal detector limitations then exist today. For example:

In a  September of 2008 I-Team investigative news story in Cleveland, local CBS affiliate station reporters walked into one Cleveland school multiple times with a hidden camera and found the two metal detectors turned off and the school’s security officer nowhere near the front entrance.  The news story indicated that officials at the school had intentionally not run the detectors to avoid delaying traffic into the building.  The district’s security chief, during a subsequent interview, stated the school officer did not follow district standards.  The school’s principal was interviewed and declined to explain on camera.

Also in September of 2008, in Milwaukee, a 15-year-old female student was stabbed several times in a restroom on the same day a $50,000 metal detector debuted at the school.  Officials reportedly said that the detector was only used on tardy students that day while staff were being trained on using the detector.  It was unknown whether the stabbing suspects had or had not been screened.

Earlier in 2008 in Memphis, a TV news reporter interviewed a teacher who indicated that school officials ran students through a metal detector that they allegedly knew was broken even after two school shooting incidents in the district.

And there are other documented incidents of weapons possession/use at schools that did have metal detectors programs at the school at the time of the incidents.

Framing the Use of Metal Detectors in Schools

We share these examples, points and questions to illustrate that there are many implementation issues and questions to consider when discussing potential use of metal detectors in schools.  It is simply not an issue of buying the equipment and running the machines, and school safety threats will be eliminated.  Too often the public does not see the complexities associated with operating a school metal detector program, nor do they understand that such a program will NOT provide the 100% guarantee of school safety they are openly or subliminally desiring and/or anticipating.

Does this mean that we recommend that no school district ever employ metal detectors?  No, but for those that choose to do so, it should only be after a comprehensive assessment of all risks and threats, as well as where limited resources could and should be deployed to meet more likely needs.

Some districts have considered random metal detector operations versus stationary metal detector programs in schools.  Random metal detector sweeps conducted from school buses, at school entrances, during the course of the school day, at after-school events, and in related manners to keep students off guard have been explored.  A random metal detector program is sometimes considered as an alternative approach to stationary detectors that bypasses some of the implementation obstacles noted above.

The key for districts using metal detectors is to present the limitations of a metal detector program to parents and the broader community in an honest and direct manner, rather than allowing the school-community to perceive metal detectors as a “cure all” or “panacea” for the district’s school safety woes.    It should be clear that metal detectors are being used as one risk-reduction tool, not as a quick-fix guarantee of school safety.  Districts using metal detectors should present them to the school-community as one component in a comprehensive school safety program.

Metal detectors are not for all districts.  In fact, it has been our experience that they are not the answer for the majority of school districts.  School leaders must consider both the financial and implementation investments of properly running a metal detector program, and determine if the potential return on investment is as great as putting those financial, manpower and operational resources into other prevention, intervention, security and preparedness strategies.

For those districts that choose to implement metal detectors, it is imporant to avoid knee-jerk reactions, ensure fidelity of implementation, and present the program to members of the school-community in a fair and honest context in terms of its capabilities, limitations and expectations.

Questions or additional suggestions may be directed to Ken Trump.