In the Treatment Center unit at the Louisiana State Penitentiary, opposite from only slightly bleaker Hospice Unit across the hall, I’ve been visiting with Shon Miller regularly for nearly two decades. Shon, chronically ill in a hospital bed from osteomyelitis and, relatedly, paraplegic from police gunfire, always greets me with an enormous, toothy smile and refers to me as “Mr. Billy,” though I have told him for many years that he can drop the “Mister.” He asks after my wife and daughters and reminds me to treasure them. He wants to hear about the lawyers and investigators who once worked on his case: “How’s Ms. Lucy? What about Ms. Cassy? I haven’t heard from her since last Christmas when I got a card.”

He lavishes attention and interest on this group of lawyers who got his death sentence reversed in 2007, and then worked with him to obtain a plea agreement with the Ascension Parish District Attorney’s Office. Shon’s case was resolved with a plea agreement requiring him to spend the rest of his life in prison without the possibility of parole, waive future appeals, and admit his guilt for his crimes in exchange for the State of Louisiana’s not seeking the death penalty.

We are the only family Shon has.

Because at Wednesday-night Bible study at the New St. John Fellowship Baptist Church in Gonzales, La., on March 10, 1999, Shon killed his 2-year-old son, Shon Jr., and his long-suffering wife, Carla, along with a kindly young church deacon, Vaniaro Jackson. Four other people in the church were shot non-fatally that night. Just earlier that evening, Shon had killed his mother-in-law, Mildred Vessel, in front of her home.

The recent string of mass killings—and the familiar debate over whether these are the unavoidable acts of “evil” men or whether earlier interventions could have prevented these horrors—has brought me back to Shon’s bedside and to that awful night at his family’s church in 1999.

As Shon’s lawyers, we plumbed the depths of his background to seek to understand and contextualize his crimes as part of our constitutional duty to demonstrate why Shon deserved to live. While the courts refer to this as “mitigating evidence,” I see our job being focused on demonstrating, on a case-by-case basis, the truth of the maxim of my teacher Bryan Stevenson, that no person is as bad as the worst thing they’ve ever done.

I promise you that Shon is not evil. Rather, his mental health history dates back to the days when he was just a toddler, when his mother died of cancer, leaving him orphaned. The trauma was so great that he ceased speaking for many months and barely ate. His well-meaning adoptive mother sought treatment for him for the first time when he was 9 years old, based on reports that he had “strange physical behavior, such as rolling of the eyes, head and neck jerking, grunting sounds, running into walls as well as other unusual mannerisms.” He was never able to keep up in school and ultimately, after being left back four times (repeating second grade twice and fourth grade twice), dropped out when he was 19, without even having finished ninth grade.

Shortly thereafter, Shon met Carla and they were married. And had a son. But this, of course, was no panacea for Shon’s chronic mental health struggles. Instead, after their marriage, he was involuntarily committed on multiple occasions because of his mental illness. The first involuntary commitment followed a suicide attempt that involved drinking a container of Spitfire cleaning fluid and a jar of aspirin. Records indicated that, over the course of three months in and out of inpatient mental health commitments, he lost 50 pounds. He was evaluated, variously, as “very paranoid,” “socially withdrawn,” “disabled socially and emotionally,” “unable to provide for basic needs and unable to make rational decisions,” and “a danger to himself and others.”

During the course of these admissions, Shon admitted to doctors that he had been “stalking” Carla and that he had “physically abused” her repeatedly.

And Carla, for her part, tried her best to keep herself and her son safe from Shon. She got a restraining order for the first time in 1998, for which she detailed Shon’s crimes against her: a severe beating, the slashing of her car tires twice in one week, a fire set at her trailer home. She reported Shon for violating his restraining order. She reported to police, mental health facilities, and anyone else that would listen that Shon had threatened to kill her, her son, and himself.

Shon was involuntarily committed for the last time on December 6, 1998, based on a finding from a doctor that he was “suicidal,” “homicidal,” “violent,” and psychotic. The triage notes indicate, “Pt’s family states pt has threatened repeatedly to kill himself and his family.” His diagnosis upon admission was psychosis. He was given a Global Assessment of Functioning score of 15 (out of 100), the second-lowest possible category of human functioning, classifying him as having “some danger of hurting self or others (e.g., suicide attempts without clear expectation of death; frequently violent; manic excitement).”

He was discharged after five days in much the same state on December 11, 1998, referred to mental health aftercare and given a prescription for psychotropic medications. He did not show up for his aftercare appointment. He didn’t take his medication.

Instead, on December 26, 1998, he went into the Bayou Pawn Shop in Donaldson, La., to buy a gun. He chose a Larson 9 mm pistol. He was asked by the salesperson to complete a standard ATF form for gun purchases. He checked “no” to the question relating to whether he was under a court order for domestic violence and “no” to the question relating to whether he had any domestic violence convictions. He walked out with the gun.

Less than three months later, on March 10, 1999, Shon, with neither a car nor money to get around, got a ride from a friend from Donaldson, where he was living in a halfway house, to Gonzalez, where Carla was living. The friend saw that Shon had a gun and asked him about it. Shon responded that it was legal and properly registered in his name. No big deal. But when they arrived at Shon’s mother in law’s home, the carnage began.

To be sure, Shon had caused great harm prior to acquiring a firearm. And, moreover, many seriously mentally ill people—especially and including women with mental illness—are not predisposed to violence.

Shon was a personification of the Venn diagram of someone likely to harm people if he obtained a gun. He had committed numerous acts of domestic violence against his former partner. He had been committed involuntarily three times in three months. He was seriously mentally ill. And yet he was able to walk right into a pawnshop and buy a gun. And could have done so legally without even an ineffectual ATF background check at a gun show or from another individual, where even those formalities are absent.

Carla, Shon Jr., Mildred, Vaniaro, and the parishoners at the New St. John Fellowship Baptist Church deserved better. What they all lost as a consequence of Shon’s being allowed to arm himself with a gun is unimaginable.

But Shon Miller also deserved better. He was in absolute and obvious crisis. He was psychotic. He told us how dangerous he was and what he was going to do if he got a gun. And we gave him a gun.

Buddhist teaching urges that, when possible, we prevent unsafe people from hurting others, because hurting others will hurt them. We harm ourselves when we harm others, particularly when they are the ones we—in our own often disordered ways—love.

I recalled this teaching when I was reading pro-gun politicians responding to the recent mass shootings in Buffalo, N.Y., and Uvalde, Tex. Texas Attorney General Ken Paxton’s statement, “We can’t stop bad people from doing bad things,” is particularly shocking in its moral poverty.

My work with Shon Miller, and scores of other men like him who have committed the worst harms imaginable, has proven Paxton wrong on both counts.

Shon, and people like him, could easily have been prevented from purchasing a gun legally. That might have been sufficient, since Shon, like many people in mental health crisis, lacked the life skills to navigate the world in a manner that would have allowed him to seek out and purchase a gun illegally. So he could have been prevented from doing this “bad thing”—the murders of three generations of his family and a decent, churchgoing young man. We let Shon Miller down in the worst imaginable way at the most vulnerable and important moment of his life.

I saw Shon Miller just after Father’s Day many years ago. He was clearly struggling, and I asked him what was going on. His honest response still haunts me: “I miss my son, Mr. Billy. I miss my family, Mr. Billy.”

None of this is, was, or will be inevitable. If there are bad people making bad choices, those people are us.