San Francisco police detective Dave Toschi worked on the Zodiac killer case in 1976. (San Francisco Chronicle/AP)

The dapper detective with dual leather shoulder holsters, long trench coat and a gruff attitude has become a classic movie character.

There was an archetype for this type of cop, a real detective named Dave Toschi who spent 34 years with the San Francisco Police Department. During that time, he worked more than 100 homicide cases.

One towered above the rest, impacting his career and becoming a pop culture phenomenon.

For nine years, Toschi chased an elusive, mysterious serial killer who plunged the Bay Area into a nightmare at the end of the 1960s: the famed Zodiac killer.

Toschi died Saturday at 86 after a long illness, his daughter Linda Toschi-Chambers told the San Francisco Chronicle on Wednesday.

He joined the San Francisco Police Department in 1953, after serving in the Korean War. The case that changed his life arrived 16 years later.

The Zodiac killer struck in 1968 and 1969, fatally stabbing or shooting at least five people in the Bay Area. He gave himself the nickname in a letter he sent to local newspapers that began “Dear Editor, This is the zodiac speaking,” according to FBI documents.

Accompanying the letter was a three-part message coded in complex cryptograms that stumped law enforcement. Two college professors eventually decoded the message after authorities made them public in a desperate bid for help, according to the FBI.

They revealed a chilling message.

“I like killing people because it is so much fun,” he wrote in code, calling murder “the most thrilling experience” and “even better than getting your rocks off with a girl.”

“The best part is that when I die I will be reborn in paradise and all the [word missing] I have killed will become my slaves,” he wrote. “I will not give you my name because you will try to slow down or stop my collecting of slaves for the afterlife.”

Toschi joined the case on Oct. 11, 1969, when he was called to investigate the execution-style murder of San Francisco taxi driver Paul Stine. It would prove to be the Zodiac killer’s last confirmed slaying, and the only one to take place in San Francisco.

He remained on the case for nine years, reportedly interviewing more than 2,500 potential suspects, until 1978 when he sent a series of anonymous fan letters to the San Francisco Examiner praising his own work on the case, the Associated Press reported. Toschi admitted to sending the notes, calling them an “ill-advised indulgence.”

The case, which was never solved, stuck with Toschi for most of his life. For about 40 years, he made an annual pilgrimage to the site of Stine’s slaying on its anniversary, Oct. 11.

“I always park exactly where I parked the radio car that night,” Toschi told the San Francisco Chronicle in 2009. “I look around the intersection and I wonder what the heck happened. Did we cover all the bases? Did we miss anything at the scene?”

“Why didn’t we get this guy?” he added. “I ended up with a bleeding ulcer over this case. It still haunts me. It always will.”

The Zodiac case raised Toschi’s profile, but he had already caught the eye of Hollywood legend Steve McQueen. The actor modeled Bullitt — the stylish, plays-by-his-own-rules San Francisco cop in the 1968 movie of the same name — after Toschi. McQueen even commissioned a copy of Toschi’s custom-made shoulder holster, which he wore in the movie, according to IMDb.

“There are bad cops and there are good cops and then there’s Bullitt,” read the movie’s tagline. That idea — that one tough, dedicated cop could bring evil men to justice — ran through movies for years to come.

Toschi’s most notable on-screen avatar was San Francisco Police Inspector Harry Callahan, better known as Dirty Harry, portrayed by Clint Eastwood.

Toschi himself was later portrayed on the big screen by Mark Ruffalo in 2007, when director David Fincher made “Zodiac,” an acclaimed film exploring the Zodiac killings.

The movie remains an enduring piece of American film, one that Toschi himself would sporadically watch. But the experience always left a sour taste in his mouth.

“I thought Ruffalo did a good job,” Toschi told the San Francisco Chronicle. “I enjoy it, but it depresses me. After I watch it I get angry at myself because I couldn’t close the case.”

Amateur sleuths have continued trying to identify the Zodiac killer over the years, but toward the end of his life, Toschi finally let it go.

“I want this case closed as much as anybody,” he told the Daily Mail in 2014. “I don’t talk about this case anymore. It was a long time ago.”

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