A parole officer testified Tuesday that he believed there was no alternative to segregation for Ashley Smith.
Rob Harris told the inquest into Smith's death in prison that she was a danger to herself or others.
As a result, Harris said his recommendations to the warden of Nova Institution were to keep the teenager isolated.
Smith was admitted directly into segregation when she arrived at the adult facility in October, 2006.
She had already spent almost her entire three years in youth custody in isolation.
A year later, when she was 19, Smith choked herself to death in a segregation cell at another prison in Kitchener, Ont.