Edmonton police "acted reasonably" during a fatal encounter with a 34-year-old man who was in the throes of a drug-induced delirium, Alberta's police watchdog has concluded.

The Alberta Serious Incident Response Team has released its findings on the August 18, 2018 in-custody death of a man who had fled a northeast Edmonton psychiatric hospital.

"While his death was tragic, the actions of the officers were not only reasonable and lawful in the circumstances, they were necessary," ASIRT said in a statement Wednesday.

"A failure to take custody of the man would have left him in a position where he presented a serious risk to himself, the family members who were present, and the officers."

In a lengthy release about the circumstances of the encounter, ASIRT said two police officers responded to the scene after the man, who had been released from Alberta Hospital on a temporary pass, showed up at a family member's apartment.

The man, who had a history of violence and weapons offences, had failed to return to the hospital as sanctioned and warrants had been issued for his arrest.

ASIRT said the man was causing a disturbance inside the apartment, appeared to be high on drugs and was "freaking out."

He was initially compliant with police but then attempted to step out onto the 14th-floor balcony.

Concerned for his safety, officers told the man that he was under arrest.

'Some use of force was necessary'

The man immediately became aggressive and resisted. Eventually he was taken to the ground where he continued to struggle against being handcuffed.

Following a struggle, the man was fully restrained. The officers used a wrist-lock as a "pain-compliance technique" to control the man but did not strike him, ASIRT said.

He was breathing and still able to speak, but was pale and sweaty. Paramedics were called but the man's condition quickly deteriorated.

To allow a mentally ill and intoxicated man access to the balcony would have been both irresponsible and highly dangerous. -ASIRT

He began experiencing difficulty breathing and stopped responding to verbal commands. One of the officers called dispatch and again asked that paramedics be dispatched to the scene, ASIRT said.

Then, the man stopped breathing.

Officers performed chest compressions on the man until paramedics arrived. The man was brought to the University of Alberta Hospital where he was pronounced dead.

ASIRT said a small plastic bag of methamphetamine was recovered from the body, along with a bottle containing 40 yellow pills of unknown origin.

The medical examiner listed the cause of death as "excited delirium syndrome secondary to methamphetamine toxicity."

A toxicology report confirmed the presence of methamphetamine and its metabolites, as well as a small amount of oxycodone in the man's system.

The struggle with police was noted as a contributing factor.

ASIRT said the officer's use of force was justified.

"Given the fact that they had been called to the residence for assistance and the fact that there was an outstanding warrant for the arrest of the man, the officers had both the lawful ability and duty to arrest him, and were permitted to use reasonably necessary force to do so," ASIRT said.

"When the man's behaviour escalated, some use of force was necessary both to ensure the safety of the man, but also to detain him.

"To allow a mentally ill and intoxicated man access to the balcony would have been both irresponsible and highly dangerous."

The outcome was one that no one present wanted. - ASIRT

ASIRT said the man had been staying in a hotel room since leaving Alberta Hospital, and a search of that room revealed "clear evidence of drug use," including methamphetamine and syringes.

ASIRT said the man's death was a "terrible event for all involved" and extended condolences to the man's bereaved family.

"The officers attended with the intention of providing assistance to both the man and his family, to ensure everyone's safety, and to have the man returned to Alberta Hospital so he could be properly treated.

"The outcome was one that no one present wanted and is an example of a situation when officers attempt to do everything correctly but there is still a tragic outcome."

ASIRT investigates incidents involving Alberta's police that have resulted in serious injury or death to any person, as well as serious or sensitive allegations of police misconduct.