CNN

There's nothing quite like Hollywood to bring attention to historical events. Big stars and multi-million dollar marketing promotions make us pay attention. Case in point: Zodiac, a film opening this weekend starring Jake Gyllenhaall and Robert Downey Jr.

Zodiac is the nickname of a serial killer who terrorized the San Francisco area beginning in late-1968. There are scores of books and Web sites devoted to the case, and it seems natural that a movie would eventually focus on it as well. Tonight, we profile one of the Zodiac's victims, Bryan Hartnell.

Hartnell was just a college kid at the time, attending Pacific Union College, just north of San Francisco. For the past four decades, he's tried to stay out of the spotlight and has succeeded in doing so, until he decided to discuss his tragic ordeal with us.

Hartnell says the sky on the day he was attacked was beautiful, the kind you might see in a postcard of San Francisco with the glistening bay and Golden Gate Bridge. So when he ran into his old girlfriend at the school cafeteria, he thought it would be a nice if they could take a drive together and get caught up on their lives.

They wound up at the edge of a scenic lake in a remote private area. They were laying down on a picnic blanket and gazing at the clear blue sky when a man suddenly approached and pointed a gun at them. He was wearing an eerie costume: a black hood and black shirt with a white symbol on the front that looked like crosshairs on a gun sight. (It would later become the Zodiac's trademark symbol.)

What happened next is one of the most horrific crimes you can possibly imagine. Hartnell was stabbed 8 times; his companion, Cecilia Shephard, between 10 and 20. She died a day later at the hospital, but was able to give a description of the attacker before she died. Hartnell, however, never saw his face. Investigators say it was one of the most brutal attacks they've ever seen. They believe the Zodiac used a knife, so passersby wouldn't hear the sound of gunshots.

Following the attack, the Zodiac killer calmly walked away leaving intentional clues as to his identity. He wanted to make it clear there was a serial killer on the loose. His next victim would be a cab driver in the heart of San Francisco.

These days, Hartnell, 57, works as a probate attorney in Southern California and is married with children. With the film's release, he thought now seemed like the appropriate time to come forward and tell his story. (He says he served as an unpaid consultant on the film.)

Those familiar with the Zodiac already know how Hollywood's version of the killer's story ends: the Zodiac has never been caught. What makes the story so interesting is the hunt for the killer and the Zodiac's headline-grabbing antics: he wrote several letters to newspapers taking credit for his crimes and also included cryptograms or ciphers that he claimed would shed light on his identity. The Zodiac craved attention. He's certainly getting his wish now.