After Philadelphia police officer Mark Dial fatally shot Eddie Irizarry, police told the public the 27-year-old had lunged at officers with a knife.

Two days later, Police Commissioner Danielle Outlaw said that wasn't true. Officials said preliminary information about the shooting was called into police radio, but that narrative was contradicted by body camera footage, which has not yet been released.

Outlaw said Wednesday that the source of the initial account is still under investigation, but she has suspended Dial with intent to dismiss for administrative violations. The announcement came one day after an attorney for Irizarry's family shared surveillance footage showing Dial shooting into the driver's side of Irizarry's vehicle and called police's initial account an "out-and-out, flat-out lie."

Policing experts told USA TODAY it is not uncommon for an incorrect version of events to be initially presented to the public even when there's video evidence to the contrary. This happens despite the increasing use of body cameras and viral bystander videos of police brutality.

"It's sad that this is not an aberration," said Rachel Moran, an associate professor at the University of St. Thomas School of Law in Minnesota. "It should be really unusual that the police would be involved in a violent event and then totally misrepresent what the person that they shot was doing. ... And unfortunately, I don't think it is very unusual."

How often do police officers lie?

A pattern of police deception has been "sufficiently documented" and has been considered an "open secret" for decades, according to Moran.

"Judges will say this happened, prosecutors will say police regularly lied, defense attorneys certainly say that, police officers themselves," Moran said. "If you go back to the 1950s, the New York Police Department actually themselves coined the term "testilying" to describe their own use of deception when testifying."

Philip Stinson, a criminal justice professor at Bowling Green State University in Ohio, has created a database of 13,600 nonfederal sworn law enforcement officers who were arrested from 2005 to 2018. His data shows that about 6.2% of the more than 16,500 criminal arrest cases involved false reports or statements. He said that not all police officers lie, but the data is "shocking."

"But what's even more shocking is that what the data are not capturing are all the instances where police officers are known to have lied, but they didn't face criminal charges specifically for lying," Stinson said. "So we assume that the problem is far greater. It's a normal part of policing in some places for police officers to lie."

Videos of high-profile killings regularly contradict initial police accounts

Lauren Bonds, executive director of the National Police Accountability Project, said that although it's difficult to track, initial police narratives have been contradicted by video evidence in several recent high-profile police killings.

"It's incredibly common," Bonds said.

In some cases, like Irizarry's, police have falsely said that the victim reached for or threatened officers with a weapon. In South Carolina, for example, former police officer Michael Slager claimed he fatally shot Walter Scott in 2015 because the 50-year-old Black man grabbed his Taser. But bystander video showed Slager shot Scott in the back and then placed his Taser by his body.

Chicago police initially said former officer Jason Van Dyke shot 17-year-old Laquan McDonald in 2014 because McDonald approached officers with a knife, and the shooting was initially determined to be justified. But a court ordered police to release dashcam video more than 13 months after the shooting, which showed McDonald was walking away when he was killed.

In other instances, police initially excluded key details about the officer's actions. On Jan. 8, Memphis police said in an initial press release that "a confrontation occurred" between 29-year-old Tyre Nichols and officers, he was apprehended after a second "confrontation," he complained of "shortness of breath," then an ambulance was called. But graphic video released by the city later showed officers brutally beat Nichols and then failed to render aid as Nichols was propped up against a car. Nichols died in a hospital three days after the traffic stop,

In 2020, police in Minneapolis initially saidGeorge Floyd died after suffering "medical distress" but did not mention that former officer Derek Chauvin knelt on Floyd's neck for more than nine minutes, as seen in bystander and body camera video.

Why do some police officers lie?

Bonds said police may continue to give incorrect information because "it's worked in the past and people are banking on the fact that nobody's going to dig in more."

Moran said the rationale of why individual officers lie even when they know they're being recorded is hard to understand, but it may be because the vast majority of body camera footage goes unreviewed.

"Of course, a very high-profile incident like a shooting is going to be different," she said. "But I don't know that in the moment people are really processing 'Oh, this is a situation where I need to be truthful versus other ones where I perhaps had the freedom to make up whatever story I want about what happened.'"

Communities of color have been raising questions about police violence and deception for decades, Moran said, but broader interest in police accountability increased dramatically after the 2014 killing of Michael Brown in Ferguson, Missouri. After a high-profile incident, departments are now often pressed for an immediate response. She said that while some departments are aware of the increased scrutiny and are concerned about communicating honestly, others still "operate under the assumption that whatever they say will go."

"Sometimes the issue is more complex, and the response needs to be a tiny bit slower and more accurate," Moran said.

Laurence Miller, a police psychologist and law enforcement trainer based in Florida, said there are legitimate reasons why an officer or anyone else in a high-stress, life-or-death situation may misremember details of the event.

"People think that memory is like a tape recorder. We're used to recording devices recording our voices, recording video, but it doesn't work that way," said Miller, author of “The Psychology of Police Deadly Force Encounters: Science, Practice, and Policy.”

Miller acknowledged that officers may have reason to lie if they are facing an investigation. He said that if the account is "completely different" from the actual circumstances, exaggerating or changing the story too frequently may indicate the officer is not being truthful.

"But again, the main lesson is that if somebody gives an account that's not the same as what you see on a videotape, it doesn't guarantee they're lying, but it often means that they are legitimately misremembering it," he said. "Accusing an officer of lying, or anybody for that matter, should be a last resort and only with very strong evidence."

'More robust mechanisms' for accountability needed to curb deception

Body cameras have been heralded as a means for the public to know exactly what happened when a police officer kills someone, but police departments are often able to control the release of that footage. In Philadelphia, police spokesperson Tanya Little said the authority to release body camera footage to a family or the public lies with the district attorney's office.

Stinson, of Bowling Green, said body camera and citizen-generated footage is "important to help keep the police honest and to serve justice," but preventing officers from being dishonest altogether would require a major change in police culture.

"They're socialized into − in many places across the country − a culture that tolerates if not encourages certain types of lies in certain types of situations," he said. "And it doesn't seem the proliferation of video recordings everywhere has changed that."

Moran said in addition to thoroughly reviewing available footage before making public statements, police departments need to do a better job of investigating and disciplining officers for all kinds of misconduct, including deception. She noted that while some internal affairs units are more objective than others, the percentage of investigations that end with the officer being disciplined is "very, very low."

"A police department that is serious about addressing officer misconduct and holding officers accountable needs to have much more robust mechanisms for investigating their officers fairly and thoroughly," Moran said.

Contributing: The Associated Press