The trial for a man accused of murdering an anti-gang activist began Wednesday with the Crown saying the victim was killed for testifying against his killer in court.

Lamar Skeete, 21, is charged with first-degree murder in the death of Kenneth Mark, 30. Mark was fatally shot on Dec. 29, 2009.

Skeete pleaded not guilty.

It's not the first time Skeete has been charged with shooting Mark.

In an incident more than a year before he was killed, Mark was in the courtyard of a building when a man, allegedly Skeete, pointed a shotgun at a woman and her young child.

Mark cradled the two in an effort to protect them and wound up shot in the back and head. He received 57 shotgun pellets in his back, the court heard.

Mark’s family says he knew the men who were accused of shooting him and testified against them in court. But the judge decided there was not enough evidence and set them free on Dec. 17, 2009.

Just 12 days later, Mark was fatally shot outside of a Dundas Street and Runnymede Road pizzeria while walking to his night shift at Walmart.

Mark "feared for his life" before he was killed, Toronto police Det. Sgt. Royce MacDonald told the court Thursday.

MacDonald and Mark had met at an anti-crime event where MacDonald urged witnesses to any crime to come forward. Mark eventually did.