Residents in the area where Nadia Gehl was shot say they heard three quick pops the morning of her death, and on Thursday the court heard from those first on the scene.
On the stand, the woman who found Gehl described how she was out jogging when she found a lifeless body on the pathway near Gehl's Kitchener bus stop.
The woman says she waved down a student who called 911, but despite the fact that emergency crews were there in minutes, there was nothing that could be done.
Jurors also watched an interview videotaped in 2010 involving the Crown and defence lawyers and an 11-year-old boy.
The boy said he had heard what sounded like firecrackers on his way to school.
He also described seeing a man in a green hat running in the area, and having seen his face for a few seconds.
A composite sketch later released by police came from the description provided by the boy.
Six months after the February 2009 death, three men were charged with murder, including Gehl's husband Ronald Cyr.
Zdenek Zvolensky and Nashat Qahwash are also charged with first degree murder.
The Crown alleges Cyr is the one who planned the murder, enlisting two friends to kill Gehl while he was at work so he could collect a half-a-million dollar insurance policy.
Cyr was allegedly having an affair and wanted out of the marriage.
The trial is expected to last seven or eight weeks and 40 to 50 witnesses could be called to testify.
