He was a Muslim man with a long beard, a desire to kill, and no plans to survive his attack. He rapidly approached his target: a military building. There was yelling and running and an attempt to stop him, but it happened too fast. Minutes later four service members lay dead, along with the suicide attacker. A fifth victim would succumb to his injuries and perish two days later.

But what if this recent shooting had not occurred in Chattanooga, Tennessee? What if Mohamad Youssef Abdulazeez had grown up in Palestine, Iraq, or Afghanistan, and committed a suicide attack there instead? Would he have been hailed as a “holy martyr” by terrorist sympathizers? Would he have been described in the news as a man solely driven by ideology, and considered by Western scholars to be “psychologically normal”?

There is still widespread confusion about the psychology of Islamic suicide attackers, whether they strike at home or abroad. Are they attempting to sacrifice their lives for an ideological cause, or do they actually want to die? The answer to this question could help redefine the concept of “martyrdom,” with global repercussions. And it may be the key to reducing the number of people who commit these deadly attacks.

According to the conventional wisdom, suicide terrorists are not mentally ill or suicidal—they are psychologically stable individuals who sacrifice themselves for altruistic reasons. As a 2009 article in Psychiatry concluded, “Stressing the importance of social psychology, [our research] emphasizes the ‘normality’ and absence of individual psychopathology of the suicide bombers.” From this perspective, those who carry out “martyrdom operations” in service of radical Islamic ideologies are the product of their contexts. They become the psychological equivalent of the American Marines who were killed in Chattanooga: both sides are willing to risk their lives—and die, if necessary—for a cause they passionately believe in. Not surprisingly, terrorist leaders love this perspective, and they use it to glorify the next wave of suicide attackers.

However, a growing number of scholars are now challenging these assumptions. Ariel Merari’s research team conducted psychological tests of preemptively arrested suicide bombers and found evidence of suicidal tendencies, depressive tendencies, and previous (non-terrorist) suicide attempts. David Lester found that many female suicide bombers seem driven, at least in part, by post-traumatic stress disorder, hopelessness, and despair. And in several recent articles, I summarize evidence of psychological similarities between suicide terrorists and people who commit nonviolent suicides, coerced suicides, and mass-murder-suicides.

At first glance, the Chattanooga shooter might have seemed like a violent but psychologically normal young man. He had been researching martyrdom for at least two years, which could be interpreted as ideological commitment. And he was not a social outcast: he apparently fit in as an “Arab redneck.” One friend who spent time with him just two weeks before the attack explained that “He was always the most cheerful guy. If you were having a bad day, he would brighten your day.” Similarly, a professor who was with him just six days before the killings recalled “I just saw the same friendly guy.”

But that is not the whole story. For those who care about accurately understanding suicide attackers, we are fortunate that this offender grew up in the United States. Investigators have access to many of his acquaintances and friends, and his family has not tried to conceal their son’s personal problems, as is common in other cultures.

Far from being a blind supporter of all radical Islamicist causes, Abdulazeez actually told a friend that ISIS “was a stupid group and it was completely against Islam.” And far from being psychologically healthy, he reportedly struggled with bipolar disorder, depression, and substance abuse, and expressed suicidal thoughts in his writings.

Once Abdulazeez made the decision to end his life, his options were immediately limited. In the Islamic religion, there are powerful prohibitions against conventional suicide, and shooting oneself in the head—which many mass murderers do—would be considered an unforgiveable crime against god.

Unfortunately, “martyrdom” has become a dangerous loophole: it is the only way Islamic suicide attackers believe they can guarantee their own death, and yet go to heaven instead of hell. In the Middle East and Asia, they typically commit suicide bombings. In the United States, they tend to use firearms instead of bombs, and plan on dying via “suicide by cop.” In both cases, these attack methods help disguise their suicidal motives. It is commonly claimed that they do not want to die, they just care more about harming the enemy than they do about their own survival.

But the disguise is wearing thin. As I have argued elsewhere, the key to deterring Islamic suicide attackers—both in the United States and around the world—is to expose their suicidal motives and close the “martyrdom” loophole, once and for all. Until suicide attackers are widely seen for the desperate, traumatized, and mentally ill people they really are—instead of “psychologically normal” altruists—America will continue to suffer Islamic mass shooters who seek glory and heavenly rewards through death.

Because we know so much about him, Abdulazeez is an important case for changing perceptions worldwide. In fact, behaviorally, he appears similar to other suicidal mass murderers. In a recent study, I found that offenders who carry out public mass killings in the United States are 12.3 times more likely to die than those who commit other types of attack. Those who strike alone are more prone to die as well. I have also found that for each additional weapon rampage shooters arm themselves with, their likelihood of dying is 1.7 times higher. With Abdulazeez we can mark each of these boxes: he was a (1) public mass killer (2) who attacked alone (3) after arming himself with three weapons. His death was almost assured.

Once we recognize Abdulazeez’s suicidal motives, the irony becomes that the first responders who killed him gave him exactly what he wanted. By contrast, in an odd twist of fate, Fort Hood shooter Nidal Hasan was shot in the spine, paralyzed, and ultimately survived his attack. Stymied, Hasan has spent the last few years trying to sabotage his legal defense so he could get himself executed.

Along with broad efforts to change global perceptions of suicide attackers, it is thus worth considering whether there is some less lethal method we could employ to more often keep these individuals alive. For those who desperately want to be killed in action, this might actually make them reconsider.