Ebrahim Raisi, the president of the Iranian regime, intends to participate in the 77th session of the United Nations General Assembly later this month.

Soon after it became clear that he might be granted permission to visit New York City for the event, a group of Iranian expatriates filed suit against Raisi in U.S. district court. They want to hold him accountable for crimes against humanity. If he sets foot in the U.S., he will be served with the legal complaint against him.

I am one of the plaintiffs.

If Raisi were openly embraced by the U.N. and/or its leading member states, it would constitute whitewashing of serious violations of international law, including what may be the greatest unresolved crime against humanity from the latter half of the 20th century. It would also grant Raisi undue legitimacy, barely more than a year after he was appointed to the position in the wake of a nationwide electoral boycott.

That boycott was accompanied by countless protests condemning Raisi as the "Butcher of Tehran." The label stems primarily from Raisi's prior role as one of the four officials on the Tehran "death commission" that oversaw major aspects of a nationwide massacre of political prisoners in 1988. The massacre killed around 30,000 people in total, with the greater portions of that death toll coming from Evin and Gohardasht Prisons, the two facilities over which Raisi had jurisdiction.

My own brother Mahmoud was serving a prison term in 1988 as a result of his taking part in rallies and distributing literature for the main pro-democracy opposition group, the Mujahedin-e Khalq (MEK). In the run-up to the massacre, my family was anticipating Mahmoud's release. But, instead, authorities summoned my other brother to Evin Prison and informed him that Mahmoud had been executed. His body was not released to us then, and now more than 34 years later, we still have no definitive information about his resting place.

Mahmoud Hassani's story is tragically typical of that which is still being told by tens of thousands of families who lost loved ones during the massacre and who have been crying out for accountability ever since. The massacre was prompted by a fatwa from then-Supreme Leader Khomeini, which specifically targeted the MEK. Its members constitute at least 90 percent of the massacre's victims. Each of the plaintiffs in the case against Raisi is a current supporter of that same organization, which has continually acquired greater organizational strength, allowing it to go on challenging the regime both domestically and internationally.

The U.N. and its member states must recognize that Tehran's fear of those challenges makes figures like Raisi an even greater threat to the Iranian people and also to the regime's foreign adversaries. Raisi's appointment last year was part of a strategy to consolidate power and suppress dissent in the wake of multiple recent nationwide uprisings.

With Raisi as its president, the regime has more than doubled its rate of executions compared to the previous year, while also initiating terrorist plots against the MEK's headquarters in Albaniaas, well as Western supporters of that organization, such as former U.S. National Security Advisor John Bolton and former Secretary of State Mike Pompeo.

These trends are indicative of Tehran's ongoing commitment to the strategies and concepts that underlay the 1988 massacre. Such trends should have been clear long before the U.S. and the U.N. signaled their willingness to host him this month. In 2019, when Raisi was head of the judiciary, he played a key role in the crackdown on a nationwide uprising that November. More than 1,500 peaceful protesters were killed that month alone, and many others were tortured at length in the months that followed.

Such crimes, coming more than three decades after the 1988 massacre, are vivid demonstrations of the Iranian regime's impunity. Raisi's presidential appointment was described by Amnesty International at the time as a "grim reminder that impunity reigns supreme." The organization's secretary general said in no uncertain terms that instead of ascending to the regime's second-highest office, Raisi "should have been investigated for the crimes against humanity of murder, enforced disappearance, and torture."

But his ascendance to the presidency is no reason to give up on the prospect of such an investigation – not even a year after his inauguration. It is certainly no reason to legitimize the Butcher of Tehran or to whitewash his past actions. But the U.S, would be doing exactly that if it grants him a visa to come to New York.

Of course, if authorities were to grant him that visa with the specific intention of presenting him with our complaint and taking steps to hold him accountable in court, that would be a different matter. But if the international community really wishes to send the message that the era of Tehran's impunity is over, Raisi should be barred from speaking at the U.N., and legal measures should be taken against him all the same.

Ahmad Hassani is a mechanical engineer. He lives in Ottawa.