During an artillery barrage last Nov. 11, Yemeni security forces killed 13 civilians in the city of Taizz. One of them was a patient at al-Rawdha Hospital, which mortar rounds and tank fire struck seven times as the wounded poured in for emergency care.

“We ran with the doctors and patients to the basement of the hospital,” said Kafa’a Wazi’ Abdu, who helped bring in wounded. “The dust and smoke from the shelling was rising in front of us. I saw a wounded man lying on the ground, motionless, in a pool of blood.”

Security forces and pro-government gangs killed at least 120 unarmed people in Taizz alone last year during the Yemeni government’s relentless assault on the movement trying to end President Ali Abdullah Saleh’s 33-year rule. Nationwide 270 people were killed in attacks on largely peaceful protests. Yet under a sweeping immunity law that Yemen’s parliament approved January 21, senior officials responsible for that bloodshed can walk away free—or in the case of Saleh, fly to the United States for medical treatment.

Saleh will go to a U.S. hospital for wounds he suffered during a bombing at the presidential palace last June. Obama administration officials say privately that they gave Saleh a U.S. visa so he won’t spoil Yemen’s election on Feb. 21 to approve Vice President Abd-Rabbo Mansour Hadi as caretaker president.

But many Yemenis are enraged at the thought of their president receiving the best medical care money can buy after his security forces repeatedly attacked civilian sites such as al-Rawdha Hospital. Some of them consider Saleh’s American sojourn evidence that the U.S. values his fickle assistance in fighting Yemen’s al-Qaeda franchise more than Yemenis’ human rights.

These heated emotions are entirely understandable. But the issue should not be where a wounded autocrat convalesces. The issue is how to hold accountable the Yemeni officials responsible for last year’s unlawful killings–including Saleh.

As part of a deal promoted by Persian Gulf states and backed by the U.S. and the European Union, Yemen’s parliament granted Saleh blanket immunity and shielded his aides from prosecution for all “political” crimes—a definition that is likely to include attacks on peaceful protesters and other civilians. In exchange, Saleh agreed to resign. This pact violates Yemen’s obligations under international law, which does not recognize amnesty for war crimes, crimes against humanity, and other serious human-rights crimes.

The U.S. and other countries should stand by Yemeni victims by insisting that justice be served for unlawful attacks on protesters, as they have done in other countries in the Middle East. Last February, for example, when the United Nations Security Council voted to refer the situation in Libya to the International Criminal Court (ICC), it sent a strong signal that the international community would not tolerate the vicious repression of protesters. Yemen’s new caretaker government should join the quest for justice.

Saleh does not face arrest in the U.S. or any other country at the moment. No judicial or law enforcement body has filed charges against him, and his exit deal gives him diplomatic immunity as head of state until he formally cedes power on Feb. 21. Looking ahead, however, there are three options for prosecuting Saleh and other Yemeni officials implicated in last year’s serious human-rights crimes.

One route would be for a Yemeni national to challenge the immunity provision in Yemeni courts. The new law contains a clause barring its annulment or appeal. But Yemen’s Constitution also authorizes the Supreme Court to rule on the constitutionality of laws. Article 51 says Yemenis can go to court to “protect their rights and lawful interests.” Article 153 of the Constitution empowers the Supreme Court to strike down unconstitutional laws.

A second route would be for the authorities in another country to prosecute those suspected of serious human-rights crimes in Yemen. War crimes, for example, are subject to universal jurisdiction, meaning they can be tried anywhere. Courts abroad are not bound by amnesties issued in Yemen.

A third option is for Yemen’s incoming government to accept the jurisdiction of the ICC over grave international crimes during the uprising. Yemen is not a party to the ICC, but it could accept the court’s retroactive jurisdiction through a formal declaration. The U.N. Security Council can also refer cases to the ICC for consideration.

In many countries around the world, Human Rights Watch has found that the failure to hold accountable those responsible for the most serious international crimes can lead to future abuses. So let Saleh convalesce where he may. Just don’t let him and his aides get away with murder.

* Letta Tayler is the Yemen and global terrorism researcher for Human Rights Watch. *