Jake Gyllenhaal Makes Pulses Race in 'Zodiac'

Jake Gyllenhaal is much more than a pretty face.

He's carried every type of film, from independent to blockbuster, and was nominated for an Oscar for his role in 2005's "Brokeback Mountain."

Of course, with his chiseled features and rugged good looks, most people would agree he's not so hard on the eyes either. Fans will see him next in "Zodiac," a new film about one of the country's most frightening cold cases. Gyllenhaal talked about his latest role on "Good Morning America."

"Zodiac" is based on the story of the Zodiac Killer, a serial killer who operated in Northern California for 10 months in the late 1960s. He coined his name in a series of taunting letters he sent to the media until 1974. His letters included four cryptograms, three of which have yet to be solved.

"He wore a mask at a certain time and a black suit and he put the sign on him," Gyllenhaal said. "When he claimed the killings, at the sites he would put the sign. One of the main suspects that they had wore a zodiac watch and sent ciphers to the San Francisco Chronicle."

An Unlikely Investigator

In the movie, Gyllenhaal plays a San Francisco Chronicle cartoonist who becomes obsessed with the killing spree and attempts to solve it.

"He was in the editorial room when they got the letters from the Zodiac Killer. … He was obsessed with puzzles and solving them, and eventually took it on himself to solve it after [the police] couldn't," he said.

Gyllenhaal's character, who is based on a man who interned at the Chronicle during the killings, isn't the typical crime investigator.

"Everything played against what you would expect," he said. "You thought the person who would solve this would be a detective or a journalist, but it was this kind, unassuming person who tried to solve it just out of interest."

Gyllenhaal said that one of the things he learned in making the movie was how much technology had changed since the late '60s.

"I joke about the advent of the cell phone. If they had them at the time, they would have solved this case in a week. They didn't have fax machines or anything. … It was impossible to solve."