The hardest truth about the killings at Kent State is that we will never understand how it could happen.

What if Alan Canfora is right? What if the newly released tape recording he’s peddling proves what he claims, that Ohio National Guardsmen were ordered to open fire on unarmed students 37 years ago?

What if he’s right that you can hear six words – “Right here. Get set. Point. Fire.” – before the barrage of bullets that left four dead and nine wounded, including Canfora?

Then what?

Proving there was an order to shoot will absolve the young guardsmen who took the blame, Canfora said.

It will never, however, explain the shootings. We still want answers – then, and now – and some answers never come.

Canfora has made a name for himself as the Kent State survivor who won’t shut up, and he has his detractors. As I wrote this column, I received an unsolicited e-mail from Bill Gordon, who wrote a 1990 book, “The Fourth of May,” reissued in 1995 as “Four Dead in Ohio.” He denounced the new tape as a fraud, insisting that “Canfora has always been the greatest source of misinformation about May 4.”

Such disclaimers have dogged Canfora for a long time.

I first met him when I was student in the late 1970s at Kent State. He was impossible to ignore and an endless source of frustration when I was editor of the Daily Kent Stater. No matter what we wrote about May 4, it wasn’t enough for him. I was 21, the same age he was when he was shot, and I was high on certainty and low on patience.

At 58, Canfora is more nuanced, more complex, than the guy captured in snapshots and sound bites. Years ago, he decided that those who advised him to work for change within the system were right. He’s worked for Ohio’s Summit County Board of Elections since 1992, and he believes that democracy is hard but worth it.

We are older now, more measured in our mutual assessments, and I am unwilling to dismiss him outright. I don’t know if Canfora is right about the tape, but he does have a right to his own memories.

When Canfora entered Kent State in 1967, he supported the Vietnam War. He was surrounded by peers who opposed the war, and he began to question his beliefs. By 1970, he was an anti-war activist. Ten days before the Kent State shootings, he attended the funeral of a high school buddy killed in Vietnam.

“I remember standing at his grave, looking my friends in the eyes and saying, ‘We have to make Richard Nixon pay for this.’ ” Days later, Nixon ordered the secret invasion of Cambodia.

On the morning of May 4, Canfora made a protest flag out of black fabric and a sawed-off broomstick and headed for campus. He remembers being scared as he faced the guardsmen’s guns pointed in his direction, but he also thought they wouldn’t shoot. Not there, not on a college campus.

The bullet ripped through his right wrist. He cowered behind an elm tree, “bullets zipping through the grass, crackling through the air.” When it was over, his friend Jeff Miller was among the dead.

Just days ago, those same memories ricocheted inside Canfora’s head again after Seung-Hui Cho opened fire at Virginia Tech.

“It was a very difficult day,” he said. “Virginia Tech was different circumstances, but … once again, mothers and fathers had to make that lonely drive to the morgue or to the hospital, and no parent should have to go through that.”

Once again, we are at a loss to understand. Experts try to explain the dangers of untreated mental illness and flawed gun laws, but we will never comprehend how one angry young man could look innocent people in the eye and then repeatedly pull the trigger.

“In both tragedies,” Canfora said, “you had extreme hatred fully armed against unarmed people.”

That is arguable. What is clear is that, in both cases, the ones with the guns destroyed lives. Even on a college campus, where everyone was supposed to be safe.

That is something we will never understand.