Police in Lethbridge say a 45-year-old woman was asleep in a family member's home early Sunday when a male came in through a patio door and began sexually assaulting her.
They say the attacker dragged her outside where he continued to sexually assault her before cutting her throat and fleeing.
The woman was taken to hospital where she required immediate surgery and where she remains in serious but stable condition.
A family acquaintance was located by police a short time later.
Police say the teen, who cannot be identified, faces charges that include aggravated sexual assault, unlawful confinement and uttering threats.
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