The video is expected to be released soon, possible later this week.
Police are reportedly bracing for backlash from the release of that video.
This incident took place on the south side of Milwaukee in January.
Police were called to a Walgreens because Brown was illegally parked across two handicap spaces.
The officers say they tried to talk to Brown but had to deploy their stun guns to arrest him.
Since that time, the arrest has been the subject of a police internal investigation.
"I have some of the same concerns that the chief has expressed over the video. I'm going to let the release of that speak for itself, but yes, I definitely have concerns after watching that video,” Barrett said.
The mayor indicated that Police Chief Alfonso Morales had a similar reaction after seeing the video.
Brown was not charged in the incident. However, he did receive a parking citation.