Alfredo Prieto, a Salvadoran man, is scheduled to be executed in Virginia today, despite evidence that he has intellectual disability which would render his execution unconstitutional.

Prieto was convicted of the 1988 murders of Rachael A. Raver and Warren H. Fulton III. At the time of his trial, Virginia law required a capital defendant to have an IQ of 70 or less in order to be considered a person with intellectual disability. Of Alfredo Prieto’s three IQ scores, two were well below 70 (64 and 66), but a third was 73. Prosecutors argued that the two scores below 70 were invalid, and a jury sentenced him to death.

In 2014, the Supreme Court ruled in Hall v. Florida that states cannot use a fixed IQ score as the measure of whether an inmate can be put to death. Intellectual disability, it said, “is a condition, not a number… Courts must recognize, as does the medical community, that the IQ test is imprecise.” Prieto’s lawyers argue that Virginia has erred by relying on the unconstitutional definition of intellectual disability to reject his claim, and that procedural technicalities are preventing them from a full and fair hearing.

“This case shows how cruel and inhuman the death penalty can be,” said Steven W. Hawkins, executive director of Amnesty International USA. “Arbitrary criteria could mean the difference between life and death. This is a broken system that must be ended entirely. Prieto’s sentence must be commuted.”

Should this execution go forward, it would be the second one this week in the United States. Amnesty International USA opposes the death penalty in all cases without exception as the ultimate cruel, inhuman and degrading punishment. As of today, 140 countries have abolished the death penalty in law or practice. The U.S. was one of only nine countries in the world that carried out executions each year between 2009 and 2013.