At that point, on the last full day of deliberations, the vote on the first of three counts was 10-2 to find Cosby guilty of digitally penetrating accuser Andrea Constand without her consent, the juror said.
The jury also voted 10-2 on the third count, that the alleged assault occurred after Cosby gave Constand drugs or intoxicants without her knowledge, substantially impairing her for the purpose of preventing her resistance, according to the juror.
And on the second count, that she was unconscious or unaware during the incident, the juror said the vote was 11-1 to acquit.
On counts one and three, the two jurors who never voted to convict were “not moving, no matter what,” said the juror, who agreed to speak to ABC News on the condition of anonymity. Other jurors changed their votes over the course of the deliberations.
A second juror told the Associated Press that the panel was almost evenly split in its deliberations. The juror who spoke to the AP confirmed that at one point the vote was 10-2 to convict Cosby on two of three counts but said three people then changed their minds.
Other jurors contacted by ABC News declined to comment.
Tensions were so high inside the small jury room that a male juror punched a concrete wall, according to a juror who spoke with ABC News.
“I think he broke his pinky knuckle,” the juror said.
“If we kept going, there was definitely going to be a fight. They had five sheriff’s deputies at the door, and they could hear us and they kept coming in because they thought we were already fighting.”
The juror told ABC News that tensions in the deliberation room were exacerbated by its small size; after sheriff’s deputies realized that reporters could see into the room through a window, the 12 had to be moved from a larger conference room.
“People couldn’t even pace” in the smaller room, the juror said. “They were just literally walking in circles where they were standing because they were losing their minds. People would just start crying out of nowhere. We wouldn’t even be talking about [the case], and people would just start crying.”
Although one additional accuser testified at trial, the juror said that accusations by dozens of other women against Cosby were not a factor in the deliberations and that when someone tried to discuss anything outside the boundaries of the trial testimony and evidence, the others would swiftly end the discussion.
“We never brought anything outside in,” the juror said. “Never. Not once. If somebody would mention something, we would cut them off.”
A majority of the jurors initially voted, in a nonbinding poll, to find the entertainer not guilty on all three counts, the juror told ABC News on Monday.
The juror said deliberations effectively ended after the jury first deadlocked after 30 hours of deliberations, but the jury pressed on for 22 more hours before giving up hope of unanimous resolution on any of the three counts.
“There was no budging” after the first deadlock, the juror said, “and there was none from there on out.”
District Attorney Kevin Steele has said that he plans to retry the case.
Dan Abrams, ABC News’ chief legal affairs anchor, found it “astonishing” that the juror said so many of the jurors changed their vote from not guilty to guilty and said he has never heard of a similar situation in such a high-profile case. However, he added, taking an initial vote is merely part of the deliberation process.
“A verdict is reached only when the jurors send back the completed verdict form and inform the judge they have reached a verdict. That did not happen here,” he said.
Abrams believes that the conditions in which the jurors deliberated could allow the defense to file a motion seeking to avoid a retrial.
“The defense could argue, for example, that if the jurors had not been forced into a different, small, cramped room, they could have come back with a not-guilty verdict. But that motion would almost certainly fail,” he said. “Appellate courts are loath to start second-guessing what jurors could have or might have done.”
While declining to detail the jury’s discussions, the juror expressed a purely personal belief that while Constand may not have known precisely what Cosby was giving her, “she did take them, and he didn’t force them on her.”
The juror also thinks that Cosby didn’t act with premeditation but took advantage of the situation.
“I think that he gave [the pills] to her, and then later, when he saw what was up, maybe he figured, ‘Maybe I’ll do something.’”
Despite the extraordinary pressure inside the jury room, the juror said, the experience ultimately brought the group — seven men and five women — closer together, and most of them are now regularly in contact by text and phone.
ABC News’ Linsey Davis, Jennifer Leong, Paige More, Nery Ynclan, Tim Ruffin and Anthony McMahon contributed to this report.
EDITOR'S NOTE: This story has been updated to reflect additional details provided by the juror to ABC News in an interview subsequent to the story's publication.