Late Friday afternoon, I received a notice from the Plano Independent School District, which runs the middle school our youngest daughter attends in Dallas, describing a new policy authorizing "random, suspicion-less metal detector searches" of students in grades 6 through 12. The district plans to use "both walk-through and hand-held metal detectors" on "random groups of students," who will be required to "remove all metallic items from their pockets and person." In addition, "backpacks, bags and personal items capable of concealing a weapon will be opened and inspected for the presence of weapons." Any student "who refuses to comply with the search process will be removed from campus and subject to disciplinary consequences."

This wholesale invasion of privacy, which is supposed to "prevent and deter students from bringing weapons to school," seems to be part of the reaction to the mass shooting that killed 10 people at Santa Fe High School near Houston last May. Yet it manifestly would do nothing to prevent such an attack. Instead it will create the illusion of safety while teaching young people that their Fourth Amendment rights are inconsequential enough to be sacrificed for such a show and that any response other than meek obeisance to arbitrary examinations of their personal effects will be met with swift and sure punishment.

According to the Supreme Court, targeted searches of public school students require "reasonable suspicion" that contraband will be discovered, which is a lighter burden than the usual standard of "probable cause" but still better than nothing. The constitutional rationale for Plano ISD's new policy, which was unanimously approved by the school board in August, is that the searches are "administrative," meaning there is no reason to believe that any particular student forced to undergo them is carrying a weapon. Perversely, this complete lack of evidence is supposed to make the searches compatible with the Fourth Amendment's ban on unreasonable searches and seizures.

The legal defense of this policy requires that the selection of students for searches be random, which explains why that word appears half a dozen times in the school district's notice. "It is a truly random process," Plano ISD spokeswoman Lesley Range-Stanton told The Dallas Morning News. I have my doubts.

According to Plano ISD, "Examples of random groups include, but are not limited to, all students in a classroom, all students in a particular section of the building, all students in a specific hallway after the tardy bell, all students entering/exiting a selected door, all students on every third bus, etc." Will school officials be rolling dice both to choose one of these methods and to make a selection based on it? If not, the process won't be truly random. Nor is picking "all students in a specific hallway after the tardy bell," which sounds like either punishment disguised as a security measure or a basis for suspicion, which random selection is supposed to avoid.

Even if we assume that the selection of students for searches will be completely untainted by discretion, the policy won't necessarily hold up in court. "In the event of a legal challenge," the Texas Association of School Boards (TASB) notes in a 2018 memo about metal detectors, "the court must balance the nature of the privacy interest involved and the character of the intrusion with the nature and urgency of the school district's concerns and the efficacy of the metal detectors in addressing the concern."

In 2003, the TASB notes, a Texas appeals court upheld "a search procedure at an alternative learning center that required all students entering the center to empty their pockets and walk through a metal detector." But that program was different from Plano ISD's in several ways that may be legally significant: It was adopted by a school that "the court deemed to be at high risk for drugs and violence," it did not include backpack searches, and it used fixed metal detectors at entrances through which all students walked in the morning, as opposed to wanding and searching "random groups" throughout the school and day.

The TASB does not cite any case in which a Texas court has approved roving metal detectors in public schools, although it notes a 1996 Florida decision upholding such a program in Dade County. In that case, however, "backpacks, coats, and other belongings" were wanded but not automatically searched.

In a 2013 University of Colorado Law Review article, University of Florida law professor Jason Nance analyzes the relevant Supreme Court cases (one involving a purse search, the other two involving drug tests) and concludes that random, suspicionless searches in public schools must be based on "particularized evidence of a substance abuse or weapons problem." In 2004, Nance notes, the U.S. Court of Appeals for the 8th Circuit rejected the Little Rock School District's random, suspicionless searches of students' belongings because they were based on nothing but "generalized concerns about the existence of weapons and drugs in schools."

By way of explaining Plano ISD's new search policy, The Dallas Morning News notes that in May "a Plano West Senior High School student was arrested on suspicion of plotting an ISIS-inspired mass shooting at Frisco's Stonebriar Centre mall." The paper also mentions the Santa Fe High School shooting that same month. Neither incident amounts to "particularized evidence" of a weapon problem at, say, our daughter's middle school.

In any case, it strains credulity to imagine that a program like the one Plano ISD has adopted would deter someone bent on mass murder. As the TASB notes regarding metal detectors at entrances, "there is no guarantee…that a metal detector will stop a determined individual with a weapon." It cites a 2005 attack in Red Lake, Minnesota, where "a student shot and killed seven people at his high school, including an unarmed security guard who was operating a metal detector at the main entrance." Periodically scanning "random groups" of students would be even less of an obstacle to a mass shooter.

When I described the new Plano ISD policy to our daughter, she reacted indignantly. My fear is that after six years of random searches she and her fellow students will see them as no big deal, having been conditioned to accept invasive, harebrained security theater as an unavoidable cost of going about their daily lives. That is not the sort of civics lesson I want my children to absorb.