Transcript for Loved ones remember impact of actress' murder at hands of stalker
Hollywood, for generations, the place where people have come from all over the country to make their dreams come true. Rebecca Shafer would come here one day to make her own stardom dreams come true. But sadly, her breakout role would lead to disaster sflchlts she didn't think there were people out there that would want to harm her. Reporter: Since she was a child, Rebecca Shafer could light up a room. This is a picture of me holding Rebecca when she was 3 to 4 months old. What can I say? I adored her. Reporter: When she was a teenager, she discovered her passion for acting. So, at 16, Rebecca made a bold decision. She left her family and friends in Portland, Oregon and moved across the country to New York. That was an extremely happy time for her. She was doing what she liked. Reporter: Almost immediately, she landed a role on the soap opera, "One life to live." It's not like we know each other real well or anything. Annie, I mean, come on. Would you get yourself together? Aren't you liberated or anything? Liberated enough to tell you where you can get off, buddy! Reporter: She then is catapulted into the big time by landing a role on a prime time show called "My sister Sam." It's a huge, huge break. Reporter: My sister Sam became a hit. And Rebecca became a rising star, landing on the cov of "Seven teen" magazine and hosting parades on CBS. I'm Rebecca Shafer and really excited to be doing this parade. The first time I saw her answering fan letters, she said look, look, I'm getting fan mail, it's great. They're telling me their problems and I'm answering them back, and it's wonderful, and I'm answering them back. And I said wait a minute, you're answering them back? It's dangerous, promise me you and she didn't promise me. Back when I was watching "Magnum P.I.", this commercial came up. Reporter: Robert Bardo was 16 when he first saw "My sister Sam". She's outgoing and bubbly and everything. He wrote a number of fan letters to Rebecca Shafer and she responded tothem, by saying yours was one of the nicest I got. The letter confirms for him that she reciprocates these feelings for him. Reporter: Bardo became obsessed with the aress and decided he had to meet her. He took a plane from his home in Tucson and went to Burbank and showed up at the lot with flowers and a teddy bear. He was met at the gate by the head of security and was told no, you cannot go onto the set, can you not meet with her. Go home. But Bardo would not be deterred. Then I was told he was very agitated and very, very angry. Reporter: It's hard to believe now, but no one alerted the police. No alarm bells went off. Rebecca had no idea the danger she was in. For the next two years, she was focussed on her career, branching out into more mature She gets a big part in a movie called "Scene from the class struggle in Beverly hills." ? My idea of taking a risk is losing my birth control pills. And it had a love scene in it. This flipped some switch in Bardo. Reporter: Shafer found herself in the running for the role of a lifetime. I'm going to make him an offer he can't refuse. And that was the role of Mary in "The godfather III". It was the talk of the town. Rebecca called us excited to be auditioning for godfather III. She has no idea her stalker is enraged over a love scene she had done in a movie. He had decide he was going to go and get a gun. No more teddy bears, no more flowers, this is it. Reporter: Bardo, now 19, had hired a private investigator who got her address from the DMV. He gets an overnight with a bag and gun and arrives early in the morning and arrives at her two people have it in their mind to get to her apartment, one is a courier for the script for godfather three. The other is her deranged stalker. One she is expect being. One is not. He rings the buzzer. When she came down and answered the door, it was Robert John Bardo. He mumbled something about being her biggest fan, showed her the autographed photograph he received in the mail. She politely excused herself, told Mr. Bardo she had to get ready for an interview. She shakes his hand, wishes him well and he goes on his way. Reporter: But he came back a second time. Now she has already dealt with him. She has other things to do. And she says to him -- this is his account we have to go with -- she says to him, you're wasting my time. Mr. Bardo stated, I forgot to give you something. Withdrew a handgun from his waist band and shot her once in the chest right into the heart. Reporter: Right after the murder, Bardo took a bus back to Tucson. The very next day, Tucson police got a call about a man running in traffic on. Freeway. He was screaming "I killed Rebecca Shafer." We went very quickly and met the detectives and Marsha Clark the prosecutor. I didn't know quite what to say to them. What do you say? Other than I'm going to fight so hard to bring her killer to justice. Reporter: Two years after her murder, Bardo was found guilty of first degree murder. My reaction was relief and the family was relieved too. It's over, it's over. He'll be in there the rest of his life, thank god. I'm sure it was a mixture of grief, sadness, some satisfaction in justice. Will it give you some kind of peace? I think it will. Reporter: Robert John Bardo was sentenced to life in prison with no possibility of parole. ABC news recently reached out to him in prison, and he responded by phone. I accept full responsibility for what I've done. My thinking was negative, and I was blaming others for things that were happening within me, but with regard to Rebecca Shafer, she was irreplaceable. I think about her every day, she should be here after I think about what I have done and I have a lot of tremendous guilt. Katy Perry, an alleged stalker arrested. Reporter: Decades later, many celebrities are still targeted by stalkers. But it led to the first anti-stalking law in the nation. A positive change borne from a senseless tragedy. She is forever fixed in our mind as the beautiful 21 year old. Those who loved her will always miss her as a person and for the unexplored potential that she as a human being had.
This transcript has been automatically generated and may not be 100% accurate.