Sexuality is a simple word for a confounding landscape of feelings, sensations and thoughts : excitement, confusion, comfort, longing, disappointment, fear, rejection.

Many people believe the powerful forces of jihadism spurred the murder of 49 people at a gay nightclub in Orlando on Sunday morning. The killer, Omar Mateen, was the son of Muslim parents from Afghanistan. He apparently called 911 to pledge his allegiance to a faraway army before he began his killing spree. His ex-wife Sitora Yusufiy said “he did practice and he had his faith”, although she added that, when she knew him, he showed “no sign” of radicalisation.

Until some concrete link emerges between those distant Isis fighters and Mateen, we have the fact of his Muslim heritage and the 911 call – the sort-of invocation of a hated but fearsome group that anyone wanting to sound fearsome themselves can deploy. That and some muddled boasts to co-workers about having links to both al-Qaida and to Hezbollah, groups that bitterly oppose one another from across the Sunni-Shia divide [1].

What of the powerful forces of sexuality ? Of shame, of belonging, of the desire to ruin what you feel you cannot have – some of the most powerful forces a psyche can contain ?

Well, we now know that Omar Mateen had, at the very least, a sustained interest in homosexuality. He wasn’t a stranger at Pulse. One regular, Ty Smith, told the Orlando Sentinel he had seen him there on at least 12 occasions [2]. “Sometimes he would go over in the corner and sit and drink by himself, and other times he would get so drunk he was loud and belligerent.” Note that Smith chose the word “belligerent” rather than “bigoted”. Angry, prone to lashing out. Not, as far as has been reported, spitting homophobic slurs. You could argue that he was engaged in reconnaissance. But why get drunk (something that is forbidden in Islam) if your aim is to scope out a field of operations ?

Then there’s his use of the dating app Jack’d. It describes itself as the “largest and fastest growing dating app for guys looking to meet guys. It’s fast, free and fun !” What was it doing on Mateen’s phone ? A means of getting his blood up ? Enraging himself so he’d be better able to fulfill his jihadist destiny ? In that case, why message Pulse regular Kevin West “on and off for a year” ?

Orlando gunman Omar Mateen was a regular at Pulse, says nightclubber
When asked why she thought he went regularly to a gay club, Yusufiy told CNN [3] : “When we had gotten married, he confessed to me about his past that was recent at that time, and that he very much enjoyed going to clubs and the nightlife … I feel like it’s a side of him or a part of him that he lived but probably didn’t want everybody to know about.” Asked if she thought he was gay, she said : “I don’t know.”

And then there’s the fact that Seddique Mir Mateen told media that Omar had been angered after seeing a gay couple kissing in public while he was out with his three-year-old son [4].

If analysts are already weighing up the implications of possible links with Isis, if presidential candidates are taking it as read that Mateen was part of a web of Islamist terror spreading across the globe, let me imagine a situation in which sex, not sectarianism, plays a part. Transgressive sexuality and conservative religion can be a toxic mix. If Mateen felt conflicted about his interest in gay men, it could have been because he believed his faith would condemn him for it. There’s no easy answer to this. “Ban religion,” say some atheists, but it’s not that simple. We must encourage the compassionate and disparage the dogmatists. Strive for conditions which promote kindness, rather than judgment.

When I interviewed him recently for another article, the distinguished psychologist Samuel Juni told me : “Running away and trying to get in touch are psychologically not contradictory ... When you’re running, part of you is running from something that you would very much like to be in touch with but you can’t.” The annihilation on Sunday morning may have been Mateen’s final attempt to run away from the thing that obsessed him.

All of this poses a problem for the likes of Donald Trump, who told his Twitter followers, as the blood on the bathroom walls of Pulse was still drying, that he “appreciate[d] the congrats for being right on radical Islamic terrorism”.

If a heady combination of shame and sexuality were part of what drove Mateen’s decisions that morning, how is that to be policed ? How can we, to borrow the language of counter-terrorism, “eradicate” the “scourge” of internalised homophobia ? Of a feeling that one’s desires are dirty and humiliating ? You can’t easily make a homeland secure against self-loathing.

Donald Trump, meet human nature, in all its messy, depraved and self-defeating complexity. Sadly, complexity was never your strong point.

David Shariatmadari