Terry Frazier had been charged with murder in the killing of 65-year-old Joseph Konopka on the evening of July 11, 2007, after Konopka allegedly hired Frazier for sex and died during a sadomasochism session at Konopka's Ashbury Street home.
Frazier was accused under the felony murder rule of committing murder during the course of a burglary and robbery. He was alleged to have taken some of Konopka's belongings that night.
On Friday, Frazier, 43, pleaded guilty to involuntary manslaughter, possession of a controlled substance, two counts of grand theft and an allegation of committing a felony while out on bail, according to district attorney's office spokesman Brian Buckelew.
Under the terms of the plea agreement, he is to be sentenced to eight years in prison on April 16, Buckelew said.
He also will pay $50,000 in compensation to Konopka's family.
Konopka was the former head of the community group Residents Against Druggies, aimed at preventing drug-related crime in the Haight-Ashbury neighborhood, and ran for city supervisor.