Alec baldwin, set to face off against the woman he says relentlessly stalked him for years. He's expected to testify in open court about a string of unsettling e-mails and behavior he endured. Abc's... See More
Alec baldwin, set to face off against the woman he says relentlessly stalked him for years. He's expected to testify in open court about a string of unsettling e-mails and behavior he endured. Abc's rob nelson has that story FOR US. Reporter: He's no stranger to a movie courtroom. We have to make the past start limiting. Reporter: Today, alec baldwin takes on the real-life role of star witness. Testifying against the woman he says made his life a living hell. You are saying you're innocent? Yes. Yes, I am. Reporter: The two first met on the set of a 2002 film, "the adventures of pluto nash." And reconnected at a dinner eight years later. N claims that meal spiraled into, a massive destructive war. He says she repeatedly harass him, showing up at his house. And sending e-mails like, say i do to you. And I need to au zsee you now. She says it was a misunderstanding and turned down a plea deal, setting up this courtroom showdown. I look forward to the justice system to run its course because I strongly believe that when all the facts will be known, it's going to be clear that I haven't committed any crime. Reporter: Prosecutors opened the trial with a dramatic reading of the most salacious e-mails. I will be in prime of my ovulation this st. Patrick's day. And the best gift from you of all would be to conceive a minibaldwin on this ireland day. More high drama is expected. The judge has had to reprimand her multiple times for her courtroom outbursts. The big question, will she sit silently in court today? Or will it be a scene straight out of a movie? For "good morning america," rob nelson, abc news, new york.
This transcript has been automatically generated and may not be 100% accurate.