Ashley Smith of Moncton, N.B., strangled herself in an Ontario prison in 2007. (Canadian Press)

Lawyers for an Ontario coroner presiding over an inquest into the prison death of a mentally ill teenager say jailhouse video her family considers key evidence would not help determine the cause of Ashley Smith's death.

A native of Moncton, N.B., Smith, 19, choked herself to death with a strip of cloth at the Grand Valley Institution in Kitchener, Ont., in October 2007.

The videos depicting Smith's treatment at Quebec's Joliette prison for women "are not sufficiently connected" to the circumstances of Smith's death to justify their being part of the inquest evidence, the lawyers said.

However, counsel Fred Duprey and Eric Siebenmorgen leave it open for deputy chief coroner Dr. Bonita Porter to obtain the videos at a later date.

"If the Joliette incidents are to be inquired at all, the video evidence of them should be obtained," the lawyers state in documents released Tuesday.

The Fifth Estate

CBC's The Fifth Estate shares the story of Ashley Smith's harrowing life and the circumstances surrounding her death.

The executive director of the Canadian Association of Elizabeth Fry Societies called the Joliette videos "shocking and disturbing" in an affidavit.

"Ashley was left in a wet security gown for an extended period of time while strapped to a metal gurney," Kim Pate said.

The videos show Smith was given injections without her consent and medical staff "threatening her with further injections," Pate stated.

Before her death, Smith had endured months of forced medication, isolation and 17 transfers from one prison to another.

As a teen, she was initially given a 90-day sentence for throwing crabapples at a postal worker. But in-custody incidents kept her behind bars.

Initially, the inquest was limited to looking at the last 13 weeks of Smith's life — the time she was in Ontario prisons — but was broadened to the last 11 months of her life in November.

"The modification of the inquest's scope does not authorize a broad examination of anything in the history of Ms. Smith pre-dating her death," Duprey and Siebenmorgen said.

Julian Falconer, the lawyer who represents the Smith family, argues Smith's treatment in various institutions is integral to the inquest.

Smith engaged in self-harming behaviours because she was not able to form therapeutic relationships, Falconer argued in a response to the coroner's counsel.

"[Smith's] inability to form therapeutic relationships was caused, in part, by her multiple transfers and her abuse at the hands of correctional and health services staff," he stated.

"Without this broader factual context, the jury will have no explanation for the self-evidently lethal self-strangulation behaviours but that Ashley intended death," Falconer argued.

The inquest is scheduled to start April 4 in Toronto.