Ross D. Franklin, Associated Press
Elizabeth Johnson, left, mother of missing baby Gabriel, sits next to her attorney Vanessa Smith, as she appears for a hearing in Maricopa County Superior Court Wednesday, March 17, 2010, in Phoenix. Johnson was released from prison Friday.

PHOENIX — An Arizona woman convicted in her young son's disappearance nearly five years ago was released from prison Friday.

Elizabeth Johnson was released from the Perryville state prison in Goodyear shortly after midnight Thursday. News footage showed her walking out of the prison and leaving in a SUV driven by her attorney, Marc Victor.

Johnson is "happy to be out, excited about her future and optimistic about how things are going to go for her," Victor told The Associated Press.

He said he arranged the early morning release with the Arizona Department of Corrections to make it less traumatic for Johnson.

Department spokesman Doug Nick said early morning releases aren't unusual but he could not specify how often they occur.

Nick said Johnson's term ended at midnight. "We have no reason to hold an inmate longer than absolutely necessary. We have no right to do that," he said.

Johnson was given a more than 5-year sentence in 2012 for custodial interference and unlawful imprisonment in the Christmastime 2009 disappearance of her then-8-month-old son, Gabriel. The baby has never been found despite searches in trash containers, a Texas landfill and elsewhere.

A jury deadlocked on a kidnapping charge, the most serious count against Johnson, who turns 28 later this month.

Johnson maintained her story that she gave Gabriel away to an unidentified couple in a park in San Antonio, Texas.

"What I have done is unbelievable," she told the judge at her sentencing hearing. "There's not really anything I can say for myself."

Johnson was credited for almost three years spent in jail awaiting trial and now faces four years' probation.

Victor said Friday that Johnson "has completely come to terms" with her conviction and incarceration.

"She's put it behind her," he said, adding later: "She feels her sentence was tough but just."

It's not clear whether Johnson herself will make a statement to the media, the defense lawyer said.

Victor said he doesn't think Johnson has decided where she'll live but she has said she wants to work with single mothers in crisis and as an advocate for prisoners' rights.