She said some bruises were shaped similar to that of fingers on a hand.
She disputed the defence's claims about the boy tripping, saying she couldn't see how a 2-year-old could catapult himself into a wall hard enough to cause so many injuries.
Children did not often die from typical falls like that around the home, she said.
The court heard that a photo taken last December by the defence showed a large stain on the brick wall, which Institute Of Environmental Science And Research (ESR) scene examiners say they never saw.
ESR forensic examiner David Neale said it was possible the stain came on to the wall after the death, especially because the photo was taken more than a year after the death, and the property was occupied by lots of people.
The trial is proceeding.