'Zodiac' detective, who was model for 'Dirty Harry,' dead at 86

San Francisco police Detective Dave Toschi is seen on the job, Sept. 15, 1976. (San Francisco Chronicle via Associated Press)

Dave Toschi, the lead detective in San Francisco's unsolved Zodiac serial-killer case of the 1960s and ‘70s, and who served as the model for charaClint Eastwood's "Dirty Harry" movie character, has died at age 86.

Toschi died Saturday at his home in San Francisco after a prolonged illness, his daughter Linda Toschi-Chambers told the San Francisco Chronicle.

Toschi's investigation into the Zodiac case began with the shooting death of a San Francisco cab driver in 1969. He was taken off the case nine years later after acknowledging he wrote and mailed anonymous fan letters to the Chronicle applauding his own work.

Between 1968 and 1969, five people were fatally stabbed or shot in Northern California and their killer sent taunting letters and cryptograms to the police and newspapers. The killer was dubbed the Zodiac because some of his cryptograms included astrological symbols and references.

The killer was never caught.

Duffy Jennings, who had grown close to Toschi through covering the killings for the Chronicle, said he visited the San Francisco murder scene on the anniversary of the killing for many years in a row to see if he overlooked any clues.

“The Zodiac case gnawed at him,” Jennings said of Toschi. “He said it gave him an ulcer.”

"The Zodiac cased gnawed at him. He said it gave him an ulcer."

— Duffy Jennings, journalist and friend of Dave Toschi

Toschi's stylish detective work immediately caught the eye of Hollywood, with Steve McQueen basing his character in the 1968 film “Bullitt” after him.

Clint Eastwood’s character Harry Callahan in the “Dirty Harry” movies also was modeled after Toschi, the Chronicle reported.

Toschi received a full portrayal by actor Mark Ruffalo in the 2007 movie “Zodiac,” based on the killings.

Toschi was born in San Francisco and graduated from Galileo High School before serving in the Korean War with the U.S. Army. He retired from police work in 1985.

He "could sing with the best of them," his daughter recalled. "His greatest pleasure was his loving family, and we will miss his keen sense of humor, his gentle guidance and his unconditional love."

Toschi is survived by his wife, Carol Toschi of San Francisco; two daughters, Toschi-Chambers of San Francisco and Karen Leight of San Mateo County; and two granddaughters, Sarah Leight of Pacifica and Emma Leight of Los Angeles.

Private services were held Wednesday.

The Associated Press contributed to this report.