The boy was tracked down by officers Friday night after they responded to a home in the city, located about 20 kilometres north of Saskatoon, where a girl was suffering from severe stab wounds.
Police managed to stabilize her at the scene and she was rushed to hospital by ambulance.
The girl was in stable condition on Sunday and is expected to make a full recovery.
Police said the two youths knew each other, but did not give details about their relationship.
"We just heard some noise, late at night some screaming," a next-door neighbour told CBC News. "We just thought some kids were goofing around in the back. My wife went out to the deck just to look and the young girl was just screaming for help and yelled to her mom that she'd been stabbed."
The neighbour said the girl was in the back of her house — where the girl's mother and great-grandmother went to help her.
"The incident happened behind the house, it wasn't actually in the house," the neighbour continued. "We just know the girl was there, and obviously somebody else."
The boy left the scene and was found a short time later by police.
The RCMP said it's believed the weapon used was a knife, which is consistent with the multiple wounds the girl suffered.
The youth is expected to make his first court appearance in Saskatoon Provincial Court on Monday.
Neither the suspect nor the victim can be named under the Youth Criminal Justice Act.
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