NEW YORK (WABC) -- Death penalty deliberations in the case against convicted ISIS terrorist Sayfullo Saipov were held up Thursday by a juror issue.
Juror #4 informed the court of a family emergency that he said would prevent him from coming to court.
Judge Vernon Broderick excused Juror #4, who informed the court his brother had suffered a heart attack and that he is "very distraught and is not coming back."
The judge said juror #4 "was despondent on the phone" and "was upset and crying" while speaking to his clerk.
"This is unlikely to be something that resolves in the short term," Broderick said. "The juror can be excused for cause on the basis of what we know right now."
The defense moved for a mistrial, invoking a strict interpretation of the federal death penalty statute that says the sentence must be put "before the jury that determined the defendant's guilt."
The judge denied the motion for a mistrial.
"There are three or four circuit courts who have considered this issue and found that courts can use an alternate even if they haven't sat in the trial phase," Broderick said.
The deliberations must now start anew with the substitution of an alternate juror. There had been fewer than three hours of deliberations on Wednesday.
The jury sent its second note at Thursday afternoon seeking clarity on what constitutes a criminal act of violence.
It reflects a prosecution argument that Saipov deserves the death penalty, in part, because he is too dangerous even for prison.
The jury asked if making verbal threats in prison constitute a criminal act of violence and whether calling for the beheadings of correction officers constitutes a criminal act of violence.
Jurors signaled they have not yet decided Saipov's sentence and would not Thursday evening.
"Your honor, we will not be able to reach a decision today," the jury said in a note to the judge.
Judge Vernon Broderick said he took the note, the third since deliberations began, to mean the jury is done for the day and wanted to start again Monday. Court does not sit on Friday.
"My reading of the note is that the jurors would like to adjourn for the day and come back on Monday," Broderick said. "If my reading is incorrect I'll send the jury back and ask them to send another note."
Outside the jury's presence Judge Broderick said the jurors were being asked to make "one of the most weighty decisions they will make in their lives."
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.
Lawyers for Saipov, an 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. Those 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.
(The Associated Press contributed to this report.)
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