An expert says there were "many red flags" warning that Howard Hyde was suffering from excited delirium in the hours before he died in a jail cell.

Christine Hall, an emergency room doctor based in Vancouver, testified Monday at an inquiry into Hyde's death at a provincial jail in the Halifax area in November 2007. He had been shocked with a stun gun 30 hours earlier.

Hall, a researcher with the Canadian Police Research Centre, says the "constant and repetitive nature" of Hyde's behaviour was one strong clue that the diagnosed paranoid schizophrenic was suffering from a condition known as excited delirium.

In Hyde's case, surveillance videotapes show him constantly pacing in his cell for hours on end in an unchanging pattern. Hall says this behaviour suggests Hyde was in a highly agitated state — a clear signal that he was suffering from excited delirium.

After Hyde's death, a medical examiner concluded that the cause of death was excited delirium, a sometimes-fatal condition stemming from schizophrenia.

Hyde, a 45-year-old musician, had a long history of paranoid schizophrenia.

Last year, the inquiry was told that Halifax police are training officers to better defuse volatile situations with the mentally ill before having to resort to the use of a Taser.

The officer responsible for training police on the use of force said last year that he expects new training guidelines will emphasize that people displaying signs of excited delirium should be treated as medical emergencies in need of immediate attention.

The inquiry has heard that some signs of the condition are profuse sweating, super-human strength, delusions and being impervious to pain— some of which Hyde displayed at the time.

Hyde was arrested following a complaint of domestic assault. He was taken to police headquarters, where he was shocked with a Taser, after becoming agitated as officers tried to fingerprint him. He died the following day at the correctional facility.

The inquiry is looking at how police officers and others in the justice system treated Hyde, who was off his medications and had been acting erratically leading up to his death.