Fascinating developments in the recent NYPD shooting of a hammer-wielding assailant. Here is what two witnesses told the New York Times shortly after the shooting.

Mr. O’Grady spoke to a reporter for The New York Times and said the wounded man was in flight when he was shot. “He looked like he was trying to get away from the officers,” Mr. O’Grady said.

Another person on Eighth Avenue then, Sunny Khalsa, 41, had been riding her bicycle when she saw police officers and the man. Shaken by the encounter, she contacted the Times newsroom with a shocking detail.

“I saw a man who was handcuffed being shot,” Ms. Khalsa said. “And I am sorry, maybe I am crazy, but that is what I saw.”

As it turns out, surveillance video has since shown that both witnesses were wrong.  It also appears from the video that the shooting was justified.

As the Times article points out, we’ve known for a long time that eyewitness testimony is unreliable, yet studies have shown that jurors tend to put more stock in it than any evidence outside of DNA. We usually hear about eyewitness mistakes in wrongful conviction cases, often in the context of false identifications due to improper lineup procedures or signaling by police (which can often be unintentional).

This story is interesting because it flips the narrative, and shows how an eyewitness’ biases can just as easily work against law enforcement. The Times went back to Khalsa for comment after the video showed she was wrong.

“I feel totally embarrassed,” she said on Thursday, after having seen the video.

She now believes that she saw the initial encounter and then looked away, as she was on her bicycle. In that moment, the man began the attack, which lasted about three seconds until he was shot. “I didn’t see the civilian run or swing a hammer,” she said. “In my mind I assumed he was just standing there passively, and now is on the ground in handcuffs.”

“With all of the accounts in the news of police officers in shootings, I assumed that police were taking advantage of someone who was easily discriminated against,” she added. “Based on what I saw, I assumed the worst. Even though I had looked away.”

As the article points out, there’s no reason to think that Khalsa was lying. False memories can seem just as real as real memories. This also likely explains why there were so many contradictory accounts of the Michael Brown shooting. People can see the same event, remember it very differently, and recount it very differently — and they can all be telling the truth about what they remember.

This is also another data point supporting the use of police body cameras. People tend to have very strong feelings about law enforcement officers, one way or the other. That will color the way they see altercations between police and suspects. (And this, of course, is also true of cops themselves.) Within reason, and without encroaching on other values, we should be doing what we can to create and preserve an independent narrative of these incidents. As the NYPD shooting demonstrates, a video can be just as effective at exonerating a police officer as it can be in implicating one.