In the wake of another horrible school massacre, the usual politicians have trotted out the same stale cries for more robust forms of gun control, including the omnipresent expanded background checks and a ban on “assault weapons.”

Not that the most stringent enforcement of these anti-gun measures would have helped prevent the Santa Fe school shooting. Why? Because the 17-year-old shooter used a shotgun and a revolver ― not assault weapons by even the wildest application of this nebulous term. And the shooter borrowed or stole the guns from a family member. No background check needed.

So, could we please stop the politicizing of these horrible mass murders in our schools and get serious about stopping them?

Our nation’s response to 9-11 may be a good model. When the Twin Towers were attacked, killing 3,000 people, no one suggested banning airplanes or “box cutters.” Instead, we looked at the facts and responded accordingly.

TSA was created and the onerous, invasive, airport experience we put up with today became the norm. Everyone gets an ID checked and goes through a metal detector. There is a no-fly list. Suspicious people get very thoroughly searched. All luggage is screened for weapons and explosives.

The result? There have been no more airplane hijackings. I sincerely hope Santa Fe is our school shooting version of 9-11.

So what about other mass shootings in our K-12 schools? Is there a pattern? What are the relevant facts?

Since Columbine in 1999, there have been “only” five mass shooting in our public schools: Red Lake, Sandy Hook, Marysville, Parkland and now Santa Fe. They are all eerily similar. Here is a recap:

March 2005, Red Lake, Minnesota

JW, the 16-year-old shooter, killed his grandfather, stole his .40-caliber Glock pistol and 12-gauge pump shotgun and drove to Red Lake Senior High School. JW, who was a troubled student at the school, walked in the main entrance, where he encountered two unarmed guards manning the metal detector. JW killed one guard and the other ran for his life. JW then proceeded to murder one teacher and five students before killing himself.

There were warning signs. Students teased and bullied the JW, who was overweight and suffered from mental illness. He had attempted suicide multiple times. Ironically, JW’s doctor increased his Prozac dose just days before the massacre.

Summary: The shooter was a troubled kid under a doctor’s care for mental illness. Neither banning assault weapons nor expanded background checks would have impacted the outcome.

December 2012, Newtown, Connecticut

AL, the 20-year-old shooter, killed his mother and stole her .223-caliber Bushmaster rifle and two pistols. AL then drove to Sandy Hook Elementary School. Upon finding the main entrance locked, AL shot out the glass in the sidelight and entered the building where, in less than five minutes, he murdered six unarmed teachers and 20 students before killing himself.

Summary: The shooter had a very troubled life. He was a mess, both physically (extreme anorexia) and psychologically. There were warning signs: AL was obsessed with mass shootings, including Columbine. The murder weapon was a “mean looking” semi-automatic rifle, which some people call an “assault rifle.” In this case, the Bushmaster, along with several other rifles and handguns, were all legally owned by his mother (a gun enthusiast).

There is no indication that, had the particular “assault rifle” not been available, the outcome would have any been different. AL had many other weapons to choose from, including a .12-gauge semi-auto shotgun that could have been used to devastating effect. And, since AL stole the murder weapon, expanded background checks would not have impacted outcome.

October 2014, Marysville, Washington

JF, the 15-year-old shooter, stole or borrowed a .40-caliber Beretta pistol from his father. Prior to the shooting, JF, who was suspended from school and from the football team for fighting, texted several friends and suggested they meet for lunch. JF then went to the Marysville High School cafeteria and murdered four of the gathered students, including a girl who had refused his romantic interests, before killing himself. It took only a few seconds. Apparently the school resource officer was not on site at the time of the shootings.

There were warning signs. A substitute teacher learned about the incipient shooting but did not pass the information on. As a result, the victims’ families sued the school and won an $18 million settlement.

Summary: The shooter was a troubled kid suffering from depression. Neither banning assault weapons nor expanded background checks would have impacted the outcome.

February 2018, Parkland, Florida

NC, the 19-year-old shooter, walked onto the Stoneman Douglas school campus carrying a duffle bag. In that bag was an Armalite .223-caliber semi-automatic rifle (an AR-15) that was legally purchased. NC was a former student at Stoneman Douglas and a very well-known troublemaker. He had no business on the Stoneman Douglas campus. Yet NC was able to walk unfettered into school building 1200 and murder 17 unarmed people. Meanwhile, the only armed lawman on campus hid outside while the killing went on unabated inside the school. Done killing, NC headed off to Subway for a soda.

To make this atrocity even more gut-wrenching, if not for the school district’s “get soft on crime” PROMISE program, it is likely that NC, who openly bragged he wanted to be a professional school shooter, would have been prohibited from legally buying the murder weapon. That legal obstacle might not have stopped him from obtaining firearms, but a school resource officer returning fire certainly would have reduced the body count.

Summary: The shooter was a very troubled kid and known to be violent. There were many warning signs, including calls to law enforcement tip lines. Since NC had access to at least 10 legally purchased firearms, banning assault weapons resembling his AR-15 most likely would not have changed the outcome.

Importantly, AL most likely would not have cleared background checks when purchasing his weapons if the school had not decided to conceal all students’ criminal behavior via the PROMISE program.

So a factual review of the recent mass school shootings reveals that these crimes were perpetrated by young males with mental illness. The schools they attacked were not secure and warning signs were ignored. In four of the five cases, the guns were stolen or borrowed, thus enhanced background checks would have had no impact on the outcomes.

The shooters used pistols or shotguns 60 percent of the time. And, when a mean-looking semi-auto rifle was used (at Sandy Hook and Parkland), the shooter also had other equally deadly weapons at his disposal. So there is absolutely no evidence banning assault weapons would have saved a single life.

For those unfamiliar with firearms: Many “hunting rifles” are semi-auto but have a handsome wood stock. Presumably, these traditional-looking rifles would not be banned as assault weapons and therefore remain available to a shooter.

What seems to be lost in this whole discussion is: Why do we, as a country, provide airport-level security at the entrances to many government buildings ― yet leave our schools largely unguarded? If I were a parent of a school-age child, I would demand my child’s school be secure. For God’s sake, the Santa Fe shooter walked into the school carrying a shotgun!

Had there been metal detectors and armed security at these five schools, 60 or 70 people, most of them kids, would still be alive.

Let’s hope the Santa Fe shooting is finally our 9-11 moment, and, as a country, we do what’s needed to make our schools safe and secure.

Randall Poulton lives in Winterport. He writes a monthly column for The Republican Journal.