Carl Girouard, 24, was charged with first-degree murder and attempted murder.
The girl died after being stabbed.
He was convicted of second-degree murder in the death of Letisha Reimer and aggravated assault in an attack on another student.
The condition of the victims has not been confirmed.
Hunter Haze Straight-Smith died after being taken off life support.
The three-year-old boy was stabbed multiple times in his sleep.
The toddler is in critical condition.
A 14-year-old boy was killed outside Winston Churchill Secondary School
The man was found guilty of stabbing a Winnipeg bus driver in 2017.
The incident took place at a bus stop on the outskirts of Tokyo.