>> The agency responsible for investigating misconduct by Chicago police officers identified a troubling pattern of undocumented and aggressive traffic stops on the Westside at least a year before officers killed decks to read.

That's according to a letter obtained exclusively by our own Heather Sharon who joins us now with details.

Heather, first, remind us what happened to Dexter read on March.

21st for officers fired 96 shots in 41 seconds.

Shortly after stopping Dexter read in a traffic stop, officers told investigators was prompted on suspicion.

>> He wasn't wearing a seatbelt.

Now those 4 officers remain on administrative leave and have not returned to active duty but have not been stripped of their police powers as the civilian office of Police Accountability recommended as they continue to investigate this shooting.

>> Okay.

So what is the letter that you obtained been tell us about his death?

That letter from the director of investigations for Copa shows that COVID had documented a troubling pattern of traffic stops.

>> And pedestrian stops in the same police district where Reid was killed.

Those stops were not documented, according to this letter in accordance with Departmental policy, nor were they recorded by officers body-worn cameras that made it impossible for Copa director of investigations said to determine whether the stops had probable cause and raises the possibility that this pattern existed for many months before Dexter Reid was killed.

But nobody in the city took any action to say, hey, we've got a problem.

So to that point, why didn't the city's misconduct agency alert?

A police superintendent Larry Snelling in its staff about this pattern Sooner.

>> Copa Chief Administrator Andrea Kirsten said they were working diligently behind the scenes to document this pattern and Marshall enough evidence to present it to the police superintendent, but simply haven't completed that work.

By the time Dexter Reid was killed, prompting them to send the letter 6 days later after his death realizing that this has become an issue of critical importance to the city as Mayor Brandon Johnson called for So how has or has CPD, you know, change the way they stop people on the West side?

Well, please, spokespeople declined to answer my questions in detail about the stops or Dexter reads Killing, which remains under investigation.

However, they did say that after rains killing officers were reminded about departmental policy and that they had to not only filed the proper reports, but record those interactions on their body worn cameras, weather that has made any difference on the West Side and Garfield Park in Humble Park.

We just don't know.

Right exclusive reporting from head to Sharon.

Thank you, Heather.

Thanks.

Brandis.