It was a series of mistakes and aggressive tactics that culminated in officers caught on video punching, kicking and beating Tire Nichols with a baton after a traffic stop in Memphis, Tennessee, this month, three retired police officers said.

Ed Davis, Boston’s police commissioner from 2006 to 2013, told NBC News on Saturday that videos of the beating of Nichols by Memphis police on Jan. 7 made him «sick.»

“It no longer makes sense to me that any police department in this country can apply that type of punishment that we saw ⁠: street justice,” Davis said. “Was it a problem in the United States? Yes it was. Is it still a problem in some places? Obviously, we see this in Memphis.»

He continued: «When you see something like this, it’s a throwback to old police procedures.»

Davis said the videos captured Memphis police acting like criminals.

“This whole incident should not be seen as a police operation. It was more of a street crime that happened between people in uniform.”

«Cops get angry when people resist»

Nichols, a 29-year-old black man who was an amateur photographer and skateboarder, was hospitalized in critical condition and died three days after the traffic stop.

Memphis authorities on Friday released videos from multiple points of view showing the aftermath of the traffic stop. The videos, three from police body cameras and one from a pole-mounted police surveillance camera, show Nichols being punched, beaten with a baton, kicked in the face and doused with an irritant.

They also caught him crying for his mother and saying that he was trying to go home. His mother said he was about 80 meters from her house when her son screamed for help. Five Memphis police officers have been fired and charged with second-degree murder and other crimes, including aggravated assault and kidnapping.

More coverage of the death of Tire Nichols

  • Timeline of Tire Nichols’ Deadly Encounter with Memphis Police
  • Tire Nichols loved his family, photographed sunsets and skateboarded.
  • Tire Nichols Video Live Updates: Reaction After Memphis Police Release Footage Showing Brutal Beating
  • Heartbreaking videos show police fatally beat Tire Nichols, who is crying for his mother
  • Tire Nichols Video: Memphis Police Release Body Camera Videos

David Thomas, a professor of forensic studies at Florida Gulf Coast University, worked as a police officer for 20 years in Michigan and Florida. He said the videos made him cry and think about his children and grandchildren who are black and could be stopped at a seemingly routine stop that gets out of hand.

Thomas noted, however, that all of the accused police officers were also black.

“This is about the culture of the police. It’s not about race,” she said.

Georgetown law professor and NBC News legal analyst Paul Butler appeared on MSNBC Saturday to discuss the release of the Nichols video.

“One of the ironies of this video is that if these officers were not in uniform and badges, the same thing that happened to Mr. Nichols could have happened to them. That doesn’t mean they aren’t as biased as any other officer. Statistically, black men and women experience the same type of threats from black and Latino officers as they do from white officers,” he said.

He added: “It is important that police departments look like the communities they are supposed to protect and serve. That is a necessary condition, but it is not a sufficient condition for equal justice policing.”

Thomas said actions like when Nichols ran away from police after being pulled out of a car and held on the ground by officers can elicit intense emotions for officers.

“The police get angry when people resist. When that anger turns into uncontrolled anger, it’s the end result of what you saw.»

Roughing up suspects running from officers was not abnormal when he began working in law enforcement in the late 1970s, Thomas said.

“Their job, they believed because you disrespected the badge, you needed to be hit and they were going to teach you a lesson. In some agencies that story is the story that’s there, and no one talks about it,” she said. “There are policies that prohibit things, then there are unwritten policies that happen that everyone knows about. If the supervisors do not control it, the actions not written, what is not written down, is simply allowed to happen because it has always been so.

Foot pursuit policies are rare nationally

Policies around foot pursuits by officers are rare, according to police experts.

Last year, Chicago police limited the circumstances under which police officers could pursue fleeing suspects. The policy change came more than a year after two-foot chases ended with officers fatally shooting a 13-year-old boy and a 22-year-old man.

According to a June statement from the department, the policy update, which provides clear guidelines for when officers can pursue a suspect, also strengthens the responsibilities of supervisors. The policy was guided by «national best practices», police said.

“The safety of our community members and our officers remains at the core of this new foot pursuit policy,” Superintendent David O. Brown said in the statement. “We collaborate internally with our officers and externally with our residents to develop a policy that we all have a stake in.”

Officers in Chicago are not allowed to chase people on foot if they suspect they are committing minor crimes, such as driving on suspended licenses or drinking alcohol in public. But they still have discretion to pursue suspects they have determined are committing or about to commit crimes that pose «an obvious threat to any person.»

In 2017, the United States Department of Justice issued a scathing report saying too many Chicago police chases were unnecessary or ended with officers shooting people they weren’t supposed to be shooting.

Memphis police did not respond to questions about the foot pursuit of Nichols after his car was stopped. The video shows that Nichols escaped while he was on the ground and an officer fired a stun gun at him. At least one officer appeared to have been hit with a chemical irritant when he was sprayed on Nichols during the initial encounter.

‘It was totally terrible management’

Body camera video shows an officer catching up with Nichols running in his mother’s neighborhood and forcing him to the ground.

Davis, the former Boston police commissioner, lamented that there were no supervisors on the scene who could have stopped the brutality.

“We pay sergeants and lieutenants to be on the street,” he said. “And your first responsibility is to control a chase and then respond to whatever is happening. And 30 minutes passed. I didn’t see any sergeants there. I saw no evidence of supervisors at that scene. It was totally terrible management,” he said.

Andrew Scott, a former police chief in Boca Raton, Florida, who is an expert witness to police practices and procedures, said the incident should not have escalated beyond the initial traffic stop, but several officers did not handcuff Nichols.

“The bottom line is that there were enough officers to do that to get him cornered and handcuffed at that traffic stop. How he was able to escape is a mystery to me.

Scott added: «It was a bizarre type of incident where the officers appeared to be inept at being able to control this young man.»