Charges against a Tampa teacher who had sex with a 14-year-old middle-school student have been dropped in one of the two counties where the incidents occurred.

Debra Lafave, 25, was charged in Marion County with lewd and lascivious battery on a child and lewd and lascivious exhibition for having sex with the now 16-year-old boy in a sport utility vehicle.

As part of a plea deal, she is already serving seven years probation and three years house arrest for similar offenses in Hillsborough County for having sex with him in a classroom and her house.

But the state attorney's office in Marion County dropped the charges there on Tuesday after a judge rejected a similar plea deal that would have allowed Lafave to again avoid going to trial — and to prison. Because the boy's family doesn't want him to testify, the prosecution didn't have enough evidence to present its case.

"I believe my mental illness had a lot to do with my actions," Lafave said in a news conference Tuesday with defense attorney John Fitzgibbons, referring to bipolar disorder. "I offer my deepest apology. I am very remorseful. I want the world to see that bipolar is real."

Before taking questions during her first public comments since the case began, Lafave thanked Fitzgibbons for fighting for her and showing that mental illnesses "cause good people to do bad things." She thanked her family and her fiancé for their "unconditional love" and said she was undergoing intensive therapy that was "helping tremendously."

Lafave told reporters that she isn't allowed to see children as part of her plea agreement, though she hopes to be a mother one day. Since she is no longer allowed to teach, she said she is pursuing a career in journalism instead.

Asked whether she thought men charged with sex crimes against children were handled more harshly by the legal system than women, Lafave said she didn't.

"I don't think there is a double standard," she said. "I think we should all check the statistics."

The Marion County state attorney's office released a statement Tuesday about dropping the charges against Lafave.

"The court may be willing to risk the well-being of the victims in this case in order to force it to trial. I am not," Florida State Attorney Brad King said. "The Florida constitution and Florida statutes make it clear that victims are entitled to protection and to have their wishes given consideration in all criminal cases. The victims have made it clear that they do not want to testify, and this position is both understandable and reasonable."

Earlier in the day, Marion County Circuit Judge Hale R. Stancil said honoring the plea agreement would undermine the credibility of the criminal justice system and "erode public confidence in our schools."

"Accepting the proposed plea agreement would likewise send the message that if enough publicity is generated, and the media's interest continues long enough, and because of that interest the victim does not wish to testify, a defendant can avoid an appropriate sentence," Stancil wrote in his decision.

"Quite frankly, if the allegations against the defendant are true, the agreed-upon sentence shocks the conscience of this court."

Normally, Stancil's ruling would have sent the case to trial. If Lafave had been found guilty of the charges, it would almost certainly have meant jail time of up to 30 years for the former teacher.

The boy's family wanted to avoid a trial and Lafave wouldn't agree to a plea deal containing a sentence of imprisonment, according to the decision.

Lafave pleaded guilty in November to two counts of lewd and lascivious battery brought against her in Hillsborough County for having sex with the boy in a classroom and her home when she was 23 and he was 14.

A judge in Hillsborough County accepted the plea deal there and sentenced her to three years of house arrest and seven years probation.

The basic terms of the plea deal in Marion County were the same, and Lafave would have served the two sentences concurrently. Stancil rejected the deal stemming from charges that Lafave had sex with the teen in Ocala, Marion County. He set an April trial date, but attorneys said they'd revise the plea agreement.

Earlier this month, prosecutors and defense attorneys begged Stancil to accept the deal on behalf of the victim and his family. A psychiatrist who examined the boy told the judge that the victim has suffered extreme anxiety from the intense media coverage surrounding the case and does not want to testify.

Hillsborough County prosecutor Mike Sinacore has said the victim's family had anticipated a trial, but the media attention prompted the boy's mother to push for a plea deal.

"There is no one that wanted to see Debra Lafave serve jail time more than myself," the boy's mother wrote in an e-mail to the Ocala Star-Banner over the weekend. But she said the welfare of her son was more important.

Even though the charges have been dropped in Marion County, Lafave will still serve out the terms of the plea deal accepted by the Hillsborough County judge.

"This time, this case is really over — and over for good," Fitzgibbons told reporters.

FOX News' Orlando Salinas, Kay Long and The Associated Press contributed to this report.