The "30 Rock" star said at the Manhattan trial of Canadian actress Genevieve Sabourin on Tuesday that he had a meal with her at the request of a friend. He added that he gave her an email address and phone number and later communicated with her about acting classes.
That's when Baldwin says Sabourin began to barrage him with as many as 30 voicemails per night and hundreds of emails that started out as lovelorn and pleading. The messages escalated into threats to insinuate herself into his now-wife's yoga class and to come to his homes, even as he implored her to stop and threatened to call authorities, according to Baldwin, who called the experience "nightmarish."
During Baldwin's testimony, Sabourin had some outbursts, including: "You're lying!"
The actress says she and Baldwin had a 2010 tryst and a two-way exchange of emails. Her lawyer says his client wasn't stalking the actor, just seeking closure after he stopped talking to her.
Baldwin and Sabourin, who has appeared in Canadian movies and TV shows, met when he had a cameo and she was a publicist for the 2002 sci-fi comedy "The Adventures of Pluto Nash."
In April 2012, Sabourin was arrested outside Baldwin's Manhattan apartment building.
Baldwin got engaged to and married the former Hilaria Thomas in 2012, after they began dating the year before. They had a daughter, Carmen, this past August.
Hilaria Baldwin also is expected to testify.
Baldwin's career has included a Tony-nominated turn as Stanley Kowalski in "A Streetcar Named Desire" on Broadway, incarnating action hero Jack Ryan in the 1990 film "The Hunt for Red October" and an Academy Award nomination for his supporting role in the 2003 drama "The Cooler."
The Associated Press contributed to this report.