The woman had reportedly died of an overdose.
The officer hasn't been named but was placed on administrative leave with pay.
He called 911 because he hadn’t taken his medication, was high on cocaine, and needed help.
The video shows an unnamed female LAPD officer being shot at point-blank range by a guy described as a gang member on probation.
Police body camera footage is touted as objective and transparent by law enforcement agencies, but a security researcher demonstrated how easy it is to manipulate and access body camera footage.
The officer then wrestles her to the ground and repeatedly punches her in the head.
The shooting comes after the fewest NYPD shootings ever last year.
Officer Blane Salamoni won't be criminally charged
Police thought he had a gun. But he was only carrying a cell phone.
Chase Sherman's mother called 911 because he was in the middle of a psychotic episode. Body camera footage shows the violent struggle between the deputies and the victim which ultimately led to his death.
Incidents where body cameras were either switched off or manipulated highlight oversight issues as police departments across the US adopt the technology.
Video recorded by a Salt Lake City police officer's body camera shows a man becoming angry and swinging a snow shovel before the cop fatally shot him.