"I flip-flopped back and forth plenty of times," said Robert Dugan, the first non-alternate juror to show his face.
Dugan said he believed Cosby was guilty after Cosby's 2005 deposition was read in court.
He said that he couldn't get past the fact that Cosby wouldn't use the word "consent" when describing his encounter a year earlier with Andrea Constand that led to charges. "I was, like, you just got caught red-handed. Like, why would you say that if you're trying to defend yourself, in my opinion," Dugan said.
Jurors deliberated for 52 hours before a judge declared a mistral.
Dugan said tensions in the jury room complicated matters.
"People were frustrated. People missed their home. People missed their kids. It was a number of things and it finally all boiled up," Dugan said.
Prosecutors are working to rebuild their case for another trial.
A different juror last week expressed concern over the prosecution's lack of evidence, and said he didn't find Cosby's accuser to be credible.