HAYWARD -- A Livermore high school teacher accused of having a sexual relationship with a 14-year-old former student walked out of state prison a free woman Tuesday after her three-year sentence was wiped away by her time served, a district attorney spokesman said.

Marie Johnson, 42, pleaded no contest in April to the nine allegations, including incidents of sexual intercourse, sex acts inside of a car and inside Granada High School, and a charge of lewd and lascivious conduct for licking the boy's neck after a basketball game. She was handed a three-year sentence in a Hayward courtroom Tuesday afternoon, plus four years of state parole.

Marie Johnson (Courtesy Livermore Police)
Marie Johnson (Courtesy Livermore Police)

Johnson, who has been in custody since her January 2012 arrest, was immediately released from custody after the hearing because the year and a half she spent behind bars were served at half time, said Eamon O'Connor, spokesman for the Alameda County District Attorney's office. She faced a maximum possible prison sentence of nine years and eight months.

"Under state law, people receive 50 percent time credit and are then released to serve the rest of their sentence on parole, unless they violate the terms of their parole," O'Connor said, noting that that percentage may increase depending on the severity of the crime.

"Why that is the case for this particular crime is a question for the state legislature," he added.

The former Granada High School math teacher was supposed to be handed her sentence May 15, but was sent to Chowchilla State Prison for 90 days so Alameda County Superior Court Judge Joseph Hurley could determine whether it would be appropriate for her to remain in prison or be placed on probation.

The court can suspend proceedings and commit an individual to state prison for the study under state law, officials say. At the end of Johnson's 90 days, the warden, a psychologist and a prison staff member filed three reports offering their opinions on whether Johnson should be granted probation or sentenced to prison.

Johnson, who initially pleaded not guilty, was arrested at the high school Jan. 11, 2012, after the boy told authorities he was being molested.

When police interviewed Johnson after her arrest, she admitted to having sex with the student, according to a probable cause statement. She was placed on administrative leave and resigned earlier this year during her dismissal process, school officials said.

Authorities say her relationship with the boy began with text messages, Facebook postings and instant messaging over the "Words with Friends" smartphone game, then graduated to sex in the teacher's car and other locations. Her four years of state parole became effective immediately following her release from prison, O'Connor said.

Contact Erin Ivie at eivie@bayareanewsgroup.com. Follow her at Twitter.com/erin_ivie.