(CNN) -- San Francisco police are saying  a man they thought was fatally shot by officers actually killed himself. Police earlier said Kenneth Harding was shot by an officer Saturday while trying to run away. But on Thursday, authorities said they found evidence that proved something different. "We believe that the  fatal wound on Mr. Harding was self-inflicted," said police Cmdr. Mike Biel. Biel revealed the new theory at a news conference Thursday at the city's medical examiner's office. Kenneth Harding died Saturday after a confrontation with undercover  officers who were doing a fare check on passengers on the city's Muni bus transit  system.
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The fatal shooting occurs in San Francisco
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"We believe that the  fatal wound on Mr. Harding was self-inflicted," police say
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Police say the bullet found in the man's head did not match the caliber authorities use
At one point, a bystander recorded cell phone  video of the situation, including a handgun that was laying on the ground near  @placeholder.