HALIFAX -- CTV News has learned a formal complaint has been filed over a traffic stop last week which ended with Halifax Regional Police using a stun gun on an unidentified man.

The incident was recorded on video by at least two cameras and those videos will play a key role in figuring out what did -- or didn't -- happen.

In the video, a number of Halifax police officers are seen using a stun gun on a man who is already on the ground.

It all unfolded on Quinpool Road and was captured on one side of the street by a passerby and on the other side by a surveillance camera.

Police have said an officer was assaulted during the incident.

A 62-year-old man was later charged and is due in court at a later date.

"The very first thing that went through my mind is, it was scary to watch," said Halifax Regional Coun. Lindell Smith, who sits on the board of police commissioners.

Smith assumes the matter will come up at a future meeting. Most complaints end up in the hands of the police chief, but every case is different.

"The commission could ask for a briefing on the incident -- in camera -- because obviously there's personal information that would have to be disclosed, but as a commission itself, there's nothing we could really talk about in public," Smith said.

And that's the case right now. All formal complaints remain confidential, following a number of possible avenues and appeals. The process could take months.

The first step after the paperwork has been filed is an investigation by police themselves.

"You know, I think it is appropriate that, when situations like this arise, that formal complaints are made so they can be investigated," said Deputy Mayor Lisa Blackburn, who is also member of the board of police commissioners.

Both councillors admit "police investigating police" isn't an ideal situation, but other professions also investigate their own.

"It's the best bad plan that we've got right now," Blackburn said.

The videos will undoubtedly play a big role in the investigation.

That's no surprise, says Rob Currie, a Dalhousie law professor, who says pocket cameras have been a game-changer in keeping authorities honest.

"That's definitely providing for more incidents, more reports, and ultimately, more accountability for public authorities -- and anyone else who's inclined to get in trouble," says Currie.

Halifax Regional Police will only say they're following procedures laid out in the provincial Police Act.

Both councillors -- and many others -- are hopeful they'll eventually learn what really happened last week on Quinpool Road.

It's not clear who filed the complaint, and that's all considered confidential during the investigation.

It may have been the man involved in the actual incident, a bystander, or someone else.

Who it was might never be known, unless the case winds up in front of the police review board, which is open to the public.