As they filed somberly from the room, prosecutors and defense lawyers declined to talk about what went on during hours of closed-door conferences with the judge, jurors and attorneys. They said only that deliberations will resume Friday.
But observers briefed on the developments, though not authorized to publicly discuss them, said one juror ignited the chaos when she revealed to her fellow panel members that she personally knew - and didn't like - a key defense witness.
The witness was Jerry Davis, a former aide to City Council President Anna C. Verna and a onetime friend and neighbor to Louis "Bent Finger Lou" Monacello, a high-ranking mob associate. Monacello had agreed to cooperate after his 2011 arrest, and his testimony as an insider became a pillar of the prosecution against Ligambi and his codefendants.
Davis was supposed to be the defense's antidote to that testimony. He told jurors that Monacello was a volatile and often angry man who obsessively disdained and hated Ligambi. That fed into the defense argument that Monacello had a motive to lie about reputed mob boss.
How the juror knew Davis and what shaped her opinion of him wasn't clear. Her decision to keep it all secret until Monacello's name came up a week into deliberations - instead of when Davis testified nearly a month ago - and then share it with the others had the judge and lawyers questioning if she had irreparably tainted the jury.
Robreno interviewed each juror individually then replayed tapes of his conversations for the attorneys and defendants. Defense lawyers ultimately asked the judge to remove the juror in question and two others who conceded that her revelation might influence their views of the case, according to two people briefed on the proceedings.
Robreno said he would decide the issue Friday morning. Three alternates - the last three - are available to take seats on the jury if necessary. That would require the panel to again start deliberations from the beginning.
Earlier Thursday, a prosecutor suggested the jury might have already lost its way.
Assistant U.S. Attorney Frank Labor noted that jurors twice asked for ownership records related to video-poker machines, material that wasn't introduced as evidence and seemed irrelevant to the charges.
Labor asked the judge to give jurors a copy of the 52-count indictment, as a road map to guide their deliberations.
"Do you think they are confused?" Robreno asked.
"We don't know what they're doing," Labor said. "But I think there is some indication that they are, perhaps, wandering in the desert."
Defense lawyers opposed the move, saying it would improperly and unfairly suggest that there was concern about the jurors' pace or progress.
"They're not in a desert at all. They're in a jury room and they are guided by 150 pages of carefully crafted written instructions or another 40 pages of verdict sheets," said Ligambi's lawyer, Edwin Jacobs Jr., about two hours before the issue over Davis erupted.
Jacobs argued that the judge had already ruled in December that jurors would not get the indictment during their deliberations. That decision shaped his closing argument, Jacobs said.
"Just because the government is displeased with the length of the jury deliberations is not a reason to change the rules midstream," Jacobs said.
Robreno agreed and denied the prosecutor's request. But he said he might reconsider and give jurors the indictment if they specifically ask for it.
"If they want to see it ... I wouldn't preclude that," the judge said.
Contact John P. Martin at 215-925-2649, at email@example.com, or follow @JPMartinInky on Twitter.