What they didn't expect was the public outrage that would follow.
The Casey Anthony jurors have been barred from restaurants, shunned by family members, and vilified online. One even quit her job and moved out of Florida, for fear of the backlash.
One male juror consented to speak with PEOPLE under the condition of complete anonymity.
"We tried very hard to separate our emotions from the evidence," he says. "Generally, none of us liked Casey Anthony at all. She seems like a horrible person. But the prosecutors did not give us enough evidence to convict. They gave us a lot of stuff that makes us think that she probably did something wrong, but not beyond a reasonable doubt."
Now that the trial is over, life "has been a nightmare," says the juror.
"I live in fear that someone will find me. I Google my name every day to see if anyone has figured out who I am. The few people that do know haven't said anything, but one of my friends told me that his wife forbid him to talk to me. My own sister cussed me out. It has ruined my life."
Inside the Deliberations
After 90 witnesses and 33 days of testimony in the courtroom, the jurors began to deliberate. "We took a vote on the [four] charges of lying to police," he says. "And it came back 12-0 to convict. That didn't take long at all."
"We took the first vote on first-degree murder," says the juror. "We were 10 to 2 to acquit. So we talked for about thirty minutes, and the two decided that they were willing to change their votes, so first degree was off the table pretty quickly."
Next up: aggravated manslaughter.
"We did our first vote and it came out half to acquit, half to convict," says the juror. "And we talked about it for a while, going through the evidence. I'd say that some people got intense, but there were no personal attacks, no real yelling. And we talked for a while, then it was 11-1 to acquit. And the guy who didn't want to acquit basically looked at us and said, 'O.K., whatever you all want.' He knew he wasn't going to convince us."
"And then we sat there for a few minutes and were like, 'Holy crap, we are letting her go free,' " he continues. "Everyone was just stunned at what we were about to do. [One of the women jurors] asked me, 'Are you okay with this?' and I said, 'Hell, no. But what else can we do? We promised to follow the law.' "
Nearly two months later, would the juror change his vote? "I've learned a lot more about the case by reading the documents," he says.
"But when we were sequestered, we could only go by what the prosecution and defense gave us. If I had to vote now, I'd probably vote for manslaughter. But we didn't get the evidence to support it before. I know people are mad at us, but we did our jobs, and I think we did them to the very best of our abilities.