A death in a luxury condo in north Toronto helped spur a police investigation that culminated in the arrest of alleged gang members and drug dealers and saw officers find a video that Mayor Rob Ford said never existed.

In June 2012, the sound of a single gunshot echoed through the ninth floor of 100 Harrison Garden Blvd., near Yonge Street and Highway 401. A 28-year-old named Hussein Hussein was killed by a shot to the chest. At the time, police said they had leads on suspects.

"There’s a lot of good video evidence and we're in the process of reviewing that right now. I expect we'll be able to identify the people at some point," said Det.-Sgt. Daniel Nielsen of the Toronto Police about the murder at the time.

As the days wore on, the case faded from the headlines. But outside the public eye, police had identified the men fleeing the shooting.

CBC News has learned those men weren't there to kill Hussein. Instead, they were friends and family members. Someone in the group — perhaps Hussein himself — had been handling a gun when it accidentally went off, police discovered.

But it wasn't case closed. In fact police had uncovered something else: the men were allegedly key players in a human pipeline trafficking guns from Detroit into Toronto.

The shooting at the condo was not the only factor in the creation of Project Traveller, as the investigation would be known, but it was a key one.

A year after Hussein’s death, 44 people were arrested in a pre-dawn raids, many targeting the Dixon Road high rises where the alleged gun operation was centered.

CBC News has also learned that Windsor model Allyson Steil was allegedly a link between members of the Rexdale gang and the men accused of smuggling guns from Detroit. Steil was arrested in Project Traveller.

Also arrested were two of Hussein’s brothers. So it was, at least in part, that accidental shooting in a north Toronto condo that helped smash open an alleged drug and gun ring, and led police to a hard drive containing a crack video that sent shock waves through Toronto City Hall.

Police revealed at the end of October that the video had been found on a hard drive seized during Project Traveller and that its contents were consistent what the media had described.

Days later, Ford publicly admitted that he had smoked crack cocaine, after denying having done so — and the video’s existence — for months.