It was up to a jury to travel back in time and determine what had happened to the girl in the little blue dress 40 years ago.

We sat down with three of them -- a door and window specialist, a food service worker, and a retired manager.

They revealed that defense attorney Ron Brower’s strategy to discredit Mike Kent seemed to work. By the time the jurors started their deliberations, many of them believed Mike's audiotaped statement was worthless.

But what did that do for Donna? Did they believe she was responsible for Michelle’s death -- or at least indirectly responsible? If the jury said yes, prosecutor Larry Yellin told them they must vote guilty.

Early on, this juror was conflicted.

Terry Coffelt: I felt she was definitely -- she was dirty on this thing. That she really was responsible for it. But I couldn't find something to really hang my hat on to say it. So I had to go with not guilty by reasonable doubt.

John Larson (Dateline NBC): Just because you felt like they just didn't--

Terry Coffelt: I just couldn't find that thing that put me over the top.

Other jurors had strong opinions about Donna as a mother.

John Larson: Can you imagine a mother-- and you're a mother-- leaving her daughter behind on the day she moves and never checking on her? And never going back?

Barbara Herron: No.

John Larson: Under any circumstance?

Barbara Herron: Under no circumstances. I mean, if you had to leave her for a week, say, because you didn't -- maybe she was ill or blah, blah, whatever. OK. But you would immediately go and get her. If you couldn't, if it wasn't possible, you would be calling. You would be talking to her. You would be doing all kinds of things. You wouldn't lose track.

This juror served as an alternate and did not participate in the deliberations.

John Larson: In the end, if you had to bet $100, who do you think killed her?

Dick Harmelink: I think she did. I think she -- she could've. He, you know, took it upon himself to do the burial for it. But had there been a natural death, wouldn't you think that both of them would've called 911?

Barbara Herron: Well, and if 911 wasn't there, they would've taken it to the hospital or called the police or--

Dick Harmelink: There was coverup. There was major coverup.

The jury took several votes over four days and each time, the numbers changed. Finally, on day four, they went over their jury instructions again and they voted one last time.

John Larson: What was it that changed your mind?

Terry Coffelt: When we finally got to that one about conspiracy, abandonment and abuse with likelihood of injury or death, and then coupled with the tool that we had that if you took a reasonable person and put them in that same scenario, what would they do alongside what Donna did? If she was a reasonable person, she would never have turned her loose -- her baby girl -- to someone like Mike. To take to someone that she had never met, more likely. And then leave state. And never check on her again.

John Larson: Guilty...

Terry Coffelt: Guilty.

In the end, though, it wasn't enough. The jury was hopelessly deadlocked at 10-to-2 in favor of a guilty verdict. The two jurors who voted not guilty did not want to be interviewed on camera. One of them, the jury foreman, said with only circumstantial evidence, the prosecution simply did not prove its case beyond a reasonable doubt.

The judge declared a mistrial. And no one agonized more than Dick Pulsifer, Michelle’s father. He says it was as if he were kicked back in time to the day when no one, not even the authorities, listened to his cries for help.

Dick Pulsifer: It means the system didn't work -- to me. In '69 when this happened, it didn't work. So, that's where I was back in 1969. That's what it felt like.

Video   Time to ‘pay’? March 14: As a missing girl’s mother goes to trial, the girl’s father says ‘She’s going to pay for what she did’ -- but the court might have something else in mind. Dateline NBC

But Donna is not off the hook. She remains in jail because the district attorney's office plans to try her case again.

Larry Yellin: I want to get back to this trial as soon as possible. A lot of our witnesses, when you have a case that's 35 years old -- are getting older. And we've lost a few people from the time we began the investigation until the time the trial started. Including Mike Kent.

Of the many questions that still haunt Dick Pulsifer, one has been painfully answered -- his little girl is dead. But through his sadness, Dick says he feels some satisfaction Donna is behind bars awaiting trial.

Dick Pulsifer: She's not out free and fancy, you know? For 34 years, she did whatever she wanted, had money, went places, did things, you know? Michelle couldn't do that, you know, now. Now, she's getting her justice, Michelle is. So she's sitting in jail. She's going to pay for what she did. I'm that confident.

So how long does a father's love last? Dick will tell you, when no one listened, his love only grew, when no one cared, he only loved her more.

The Orange County District Attorney's Office says Donna Prentice could be retried this summer. Monday, March 17 is Michelle's birthday. 'The Girl in the Little Blue Dress' would have turned 42.

MORE FROM CRIME STORIES

Crime stories Section Front

Justice halted: The murdered prosecutor Hard lessons: Teacher-student love turns lethal Bullies caught on tape: Aggressors, or victims? Clark Rockefeller: Famous name, infamous life How the phony French 'Rockefeller' conned Americans The crossbow incident Mystery of the missing millionaire The devil's business Deadly intentions Murder on the mind Crime stories Section Front   Add Crime stories headlines to your news reader: