Ashley Smith died on Oct. 19, 2007, after she was found unconscious in her cell. (Courtesy of Ashley Smith's family)

The warden of a women's prison in Nova Scotia is telling an inquest in Toronto that he underestimated how difficult Ashley Smith would be as an inmate.

Alfred Legere said staff at Nova Institution knew Smith was self-harming and had some "extremely difficult behaviours."

As a result, authorities placed the teenager in segregation as soon as she arrived from youth custody in October 2006.

Still, Legere says Smith, 18, immediately alarmed guards by smearing feces on her cell camera and by throwing her excrement at them.

Smith also managed to "destroy" two segregation cells within days of arrival at Nova.

Smith would choke herself to death a year later at a prison in Kitchener, Ont.

Smith was first incarcerated at age 15. She was 19 when she tied a piece of cloth around her neck while guards, who were ordered not to intervene, stood outside her cell door and watched.

Since the inquest began on Jan. 14, there has been testimony from Smith's mother, several guards and a prison supervisor who said they were uncomfortable with orders to ignore Ashley and not enter her cell to remove ligatures around her neck as long as she was breathing.

with files from CBC News