The investigator who laid a second-degree murder charge against Const. James Forcillo in the shooting death of Sammy Yatim said the incident shows the need for police to have body-worn cameras.

Ian Scott was the executive director of the province's Special Investigations Unit (SIU) in July 2013, when Forcillo shot Yatim from the street as the teen stood aboard an empty streetcar. The SIU is called in to investigate incidents of injury or death during civilian interactions with police.

It was video from the cameras on the streetcar that led to the charges against Forcillo, Scott told CBC's Metro Morning on Tuesday, images that "indicated in my view excessive use of force."

Those videos, as well as interviews with both police and civilian witnesses, made a "compelling" case for laying charges against Forcillo, Scott said.

With the case hinging on the video evidence, Scott said, the force should consider body cameras for all officers.

"It's very, very difficult to analyze what happened in these circumstances without video imagery," Scott said. "And in my view it's only the video imagery that led to any finding of guilt in the Forcillo case."

On Monday, after six days of deliberations, a jury found Forcillo guilty of attempted murder, but not guilty of second-degree murder. The defence has filed a stay of proceedings in the case, and lawyers will return to court in May to deliver motions.

'Let's get some lessons out of this'

Video from a body camera may have allowed Forcillo's superiors to identify any training-related issues that needed to be addressed. His trial heard that the officer had drawn his firearm a dozen times over three-and-a-half years, but it was unclear what, if anything, was done.

"If the administration of the Toronto Police Service had the opportunity to look at, say, 10 of the last times he drew his weapon and could properly analyze and say to him, 'look Const. Forcillo, you're over-using this, you need more training,' perhaps we wouldn't have had the Sammy Yatim tragic incident," Scott said.

"So as difficult as this situation is — and let's face it the criminal justice system is probably the most blunt form of mechanisms we have in our society to deal with social control — let's get some lessons out of this so we can learn."

Police union president Mike McCormack said the verdict sent "a chilling message" to police officers. However, Scott said the message could be constructive.

"Perhaps the message should be a chilling message in the sense of, 'don't use force so quickly,'" Scott said. "'Don't use lethal force as quickly as was used in the Forcillo case.'"

Scott also would like Toronto Police Chief Mark Saunders to say that he accepts the verdict, and will adopt all of the 84 recommendations of the report by former Justice Frank Iacobucci on the use of force by Toronto police, which was spurred by the Forcillo-Yatim case.

Many of the recommendations relate to training, as well as revisions to the force's use-of-force model.

"And I'd like [Saunders] to say 'that this indicates the value of video imagery and therefore I will be promoting body-worn cameras among all of my officers,'" Scott said.