OSHAWA, ON -- The defence attempted to punch holes in the Crown's case against Michael Monckton Tuesday by suggesting some of Keagan Davis' injuries happened long before the accused child killer moved in with the tot and his mom.

Under cross-examination, Leigh-ann Worrall said her former boyfriend began living with her and her two-year-old son in the first couple weeks of November 2009, and prior to that, he would not have been alone with Keagan.

"That's a total of seven weeks," defence attorney Ray Boggs said, as he questioned the dead boy's mom about the time period leading up to her son's death on Jan. 5, 2010.

Boggs also pointed out that Monckton, who has pleaded not-guilty to second-degree murder, only took over child-care duties for Worrall after he was laid off Nov. 30, 2009.

And he reminded the court forensic pathologist Dr. Michael Pollanen, who testified earlier in the trial, acknowledged some of Keagan's injuries occurred "weeks to months" -- and possibly up to a year -- before the child's death.

"That's far beyond the dates Michael even knew Keagan," Boggs said.

Worrall began dating Monckton in August 2009. During her cross examination, she said her former boyfriend and Keagan were affectionate with each other and Monckton treated him like his own son.

Worrall, 26, also said she never saw Monckton hit or hurt her child, who she admitted was accident prone and bruised easily.

The defence also showed a photo of the accused helping Keagan take his first shower, a picture the toddler's mom shot nine days before her son died.

"They both have big, wide smiles," Boggs pointed out.

The Crown used the same photo earlier in the trial to show the boy's stomach wasn't bruised at that point.

Monckton, 28, was home alone with Keagan the day he died.

Pollanen testified that at the time of death, the tot had compressed vertebrae, broken ribs, two broken fingers, a broken forearm and internal bleeding in his stomach.

The pathologist, who concluded Keagan likely died of abdominal trauma, said some injuries were recent and others were healing or healed.

The defence argues the recent injuries were inflicted as Monckton performed CPR.

The trial resumes Wednesday.