Kajieme Powell: St Louis police shooting video stirs debate
22 August 2014 Last updated at 00:00 BST
When Kajieme Powell was shot dead by officers in St Louis on Tuesday the city's police chief immediately made clear that the 25-year-old was armed with a knife and posed a threat to their safety.
Keen to avoid the protests which happened in nearby Ferguson in the aftermath of the police shooting which left Michael Brown dead, Sam Dotson promised that the investigation would be "transparent" .
On Wednesday the police released a video filmed by an eyewitness which they said was further evidence that deadly force was justified.
But that video, watched by hundreds of thousands online, has proved controversial. Some claim it contradicts the initial police account and many argue the police could have handled the situation differently.
As the US debates when an officer should discharge his or her weapon, the BBC's David Botti looks at what the new video tells us.