In the United States city where Australian woman Justine Damond was killed, all police are required to wear body cameras. So why did the officer who shot her have his turned off?
Both police officer Mohamed Noor and his partner's body cameras were off, and their car's dashboard camera did not capture the moment Ms Damond was shot more than once, in her pyjamas and apparently unarmed, from the vehicle's passenger seat in a Minneapolis alley.
The officers were responding to a 911 call by Ms Damond, who reported hearing a possible assault in an alley behind her home.
Questions have been raised about why there was no police footage of the incident, with all Minneapolis officers required to wear body cameras since the end of 2016.
"I have the same question everyone else has: 'Why weren't the body cameras activated?'" Minneapolis Mayor Betsy Hodges said.
Did the officers break body cam policy?
The Minneapolis Police policy and procedure manual says body cameras should be activated "as soon as possible, but before any citizen contact" and "prior to any use of force".
"If a BWC [body-worn camera] is not activated prior to a use of force, it shall be activated as soon as it is safe to do so," it says.
While the Minnesota Bureau of Criminal Apprehension is investigating the shooting, it will be the Minneapolis Police Department's job to determine whether the officers violated its body camera policy.
The American Civil Liberties Union of Minnesota (ACLU-MN) said the police officers violated the policy by not turning their cameras on when they encountered Ms Damond.
"This violation of policy thwarted the public's right to know what happened to Ms Damond and why the police killed her," ACLU-MN's Teresa Nelson said.
"The two officers broke the policy, not only when they didn't activate the body cameras before the incident, but also when they failed to do so after the use of force."
Police officers must turn their body cameras on to record, but the Minneapolis Star Tribune reported they also "constantly record a 30-second video buffer, a so-called 'lookback' that allows officers to capture whatever happened in the half-minute before it's activated".
There has been no evidence that feature was used by the police officers either.
Police car dashboard cameras can also be turned on manually, and are automatically activated when the vehicle's lights and sirens are turned on.
Could officers face consequences for not turning cams on?
Ms Nelson called for consequences to be added to the policy "to ensure better compliance and accountability".
"These two officers should face penalties for breaking [the] policy … and making the truth so much harder to find," she said.
But Radford University's Professor Tod Burke said it may not be clear-cut why the body cameras were not activated and whether it constituted a breach of procedure.
"It depends if the cameras were attempted to be switched on and they just simply weren't functioning," Professor Burke told ABC News.
"So we don't know the answer to that until the investigation takes place."
Professor Burke — a former Maryland police officer — said it could also be possible the officers "simply forgot".