Death penalty deliberations in the case against convicted ISIS terrorist Sayfullo Saipov were held up indefinitely Thursday by a juror issue.

Juror #4 informed the court of a family emergency that he said would prevent him from coming to court.

It was not immediately clear to the judge whether he meant that the juror could not come back at all or for a period of time.

According to the statute, a death sentence must be imposed by the same jury that convicted a defendant. It’s left to interpretation whether that means the exact same 12 jurors or whether an alternate could substitute.

The judge laid out three options: pause deliberations for an indefinite period until juror #4 can resume, substitute an alternate or declare a mistrial.

The lawyers are conferring.

Lawyers for Saipov, a Uzbekistan citizen, never contested that he killed eight people by speeding a rented truck across a bike path in lower Manhattan that is popular with tourists. Killed were a woman visiting from Belgium with her family, five friends from Argentina and two Americans. Eighteen others were seriously injured.

Saipov’s attorneys asked jurors to spare him the death penalty, noting how several members of his family including his father and sisters expressed hope that someday he would realize how wrong he was to carry out a terrorist attack hoping to win favor with the Islamic State group.

And they emphasized that he would spend the rest of his life in seclusion, likely confined to a small cell for at least 22 hours a day with two 15-minute phone calls allowed each month to his family and a few showers permitted each week.

Prosecutors urged death, saying Saipov never showed compassion for any of his victims as he sought to kill as many people as he could, even confessing that he had hoped to go to the Brooklyn Bridge after the bike path assault so he could kill more people there.

Afterward, they said, he smiled proudly as he told FBI agents about his attack, even requesting that they hang the flag of the Islamic State organization in his hospital room, where he was recovering from a gunshot wound after a police officer ended his attack.

A day after the attack, then-President Donald Trump tweeted that Saipov “SHOULD GET DEATH PENALTY!”

After Joe Biden became president, his attorney general, Merrick Garland, announced a moratorium on federal executions, though he has allowed U.S. prosecutors to continue advocating for capital punishment in cases inherited from previous administrations.

A federal jury in New York has not rendered a death sentence that has withstood legal appeals in decades, with the last execution in 1954. New York state, which no longer has the death penalty, has not executed anyone since 1963.