In 1989, an obsessed fan knocked on Rebecca Schaeffer's door. It led to her murder.

It was July 18, 1989, and actress Rebecca Schaeffer was excitedly preparing an audition for a potentially life-changing role in The Godfather Part III. The 21-year-old was also waiting for a script to be delivered to her home.

The doorbell rang.

Schaeffer didn't know it then, but she had only an hour left to live. Because the man standing on the other side of her front door was the man who was going to murder her.

Who was Rebecca Schaeffer?

Schaeffer was the only child of Benson and Danna Schaeffer. She was passionate about both modelling and acting, and starred in print and television commercials from a young age. 

Her first role was on the drama TV series One Life to Live in 1984, followed by small roles in other shows. It was only after auditioning for new series My Sister Sam in 1986 that Schaeffer caught her big break. She landed the role of 16-year-old Patti, who goes to live with her sister Sam (played by Pam Dawber, who is married to NCIS's Mark Harmon) after their parents pass away.

Initially, the series was a big hit. But after season one, ratings dwindled, and the show was cancelled in 1988, midway through season two. Twelve episodes never made it to air.

However, Schaeffer's popularity and fame had risen exponentially during her time on the series. She was even the cover star of Seventeen magazine in 1987.

Schaeffer on the cover of Seventeen magazine in March 1987. 

After My Sister Sam ended, the actress went on to star in 1989's Scenes from the Class Struggle in Beverly Hills, as well as Voyage of Terror: The Achille Lauro Affair and The End of Innocence, both of which were released in 1990 after her death.

What happened the day Rebecca Schaeffer was murdered?

A disturbed 19-year-old man named Robert John Bardo had been stalking Schaeffer for about three years, after seeing her in My Sister Sam. He had written several fan letters to her, and she had answered at least one. Twice he had been turned away by Warner Bros security after coming to visit Schaeffer on the set of her sitcom.

Bardo had previously been obsessed with 13-year-old Samantha Smith, an actress and child peace activist who died in a plane crash in 1985. He had also been obsessed with 80s pop singers Tiffany and Debbie Gibson, as well as Madonna.

After watching Schaeffer in an intimate scene from Scenes from the Class Struggle in Beverly Hills, he grew jealous and even more crazed. He decided he would "punish" the actress by taking her life.

At that point, he did not know her home address. But he read a magazine article about psychopath Arthur Richard Jackson, who had stalked and stabbed actress Theresa Saldana in 1982 (Saldana survived but died later from pneumonia complications in 2016). Jackson had found out Saldana's home address by hiring a private investigator – inspiring Bardo to use the same trick.

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On that fateful day on July 18, 1989, Bardo knocked on Schaeffer's door. He had the card she had sent to him and her autographed photo. According to Bardo's statement later, Schaeffer greeted him and smiled, and they had a brief conversation where he told her how much of a fan he was. She told him to "please take care", shook his hand, and shut the door.

Bardo went to a diner across the street, had breakfast, and returned to Schaeffer's home an hour later. He told police it was to give her a letter and CD. But he grew angry when Schaeffer was "curt" with him. He pulled out his gun and shot her point-blank in the chest, killing her.

"She was just screaming," Bardo said, according to the LA Times. "She was going, 'Why, why?'... I was still fumbling around, thinking I should blow my head off and fall on her."

As he ran from the scene, Bardo threw a copy of The Catcher in the Rye, the same thing convicted killer Mark David Chapman did when he murdered John Lennon in 1980. According to ABC News, he was found running down the freeway in Tucson, Arizona yelling, "I killed Rebecca Schaeffer."

Rebecca Schaeffer's legacy.

In 1991, Bardo was found guilty of first degree murder and sentenced to life in prison without the possibility of parole. He is now 53 years old and remains incarcerated today.

Before she died, Schaeffer was dating television and film director Brad Silberling (Casper, City of Angels). In 2002, Silberling released the film Moonlight Mile, which was influenced by the actress' death.

Schaeffer's grief-stricken co-stars from My Sister Sam – Pam Dawber, Joel Brooks, David Naughton, and Jenny O'Hara – reunited to film a public service announcement in her honour for the Center to Prevent Handgun Violence.

A year after the tragedy, the state of California passed the first ever anti-stalking law in the US. The law states it is a "felony to cause another, or their family, to be in reasonable fear for their safety" and breaking the law carries a state prison sentence.

The law is now recognised in all 50 states across America.

Feature image: Getty Images.