New Brunswick's ombudsman is launching a probe into the death of a 19-year-old woman from the province who died in an Ontario prison.

Ashley Smith, 19, of Moncton was found unconscious in her cell at the Grand Valley Institution for Women in Kitchener, Ont., on Oct. 19. She later died in hospital.

An autopsy revealed Smith died of what police are calling "self-initiated" asphyxiation.

Waterloo Regional Police wouldn't comment further on the circumstances of Smith's death but confirmed she didn't hang herself.

Prison guards Karen Eves, 52, of Kingston, Ont., Valentino Burnett, 47, of Stoney Creek, Ont., and Blaine Phibbs, 31, of Caledonia, Ont., were on duty at the time of the incident and have been charged with criminal negligence causing death.

Police said the charges against the guards are related to "duty-bound circumstances" and "obligations and responsibilities of people in authority."

They are scheduled to appear in court in December.

Four other guards and a supervisor have been suspended without pay.

Ombudsman Bernard Richard said he'll examine Smith's time in New Brunswick's justice system and why she wasn't transferred to a federal women's prison closer to home.

Richard will also be looking at the availability of mental health services for inmates.

Smith received a six-year sentence in Moncton in 2003 for offences that included assault with a weapon, assaulting a peace officer, uttering threats and possession of a prohibited weapon in a vehicle, said Lynn Brunette of Correctional Service Canada.

Smith was a young offender when she began serving her sentence in October 2003. She would have been eligible for release in November and it is not clear when or why she was transferred to Grand Valley.

Such decisions are made on a case-by-case basis, Brunette said.

Tragedy 'predictable and preventable'

"This young woman was transferred all across the country in several different jails in less than two years that she was in federal custody, and there are a number of investigations outstanding," said Kim Pate, executive director of the Canadian Association of Elizabeth Frye Societies.

"This tragedy was both predictable and preventable," Pate said. "Without wanting to jeopardize in any way the criminal investigation, let's just say there's a whole story to come out."

Many of the women in the justice system who have severe mental health issues never receive appropriate care in a prison, Pate said.

Smith was kept in segregation for long periods in youth custody and for much of her several months in the adult system, Pate said.

Pate said she hopes investigators will recognize the added harm of isolating the most distraught and unstable inmates and that the current investigation will lead to changes in the way the justice system deals with people with mental illness.

Correctional institutions are not a substitute for mental health facilities, she said.

With files from the Canadian Press