An Edmonton man who started a fatal arson fire three years ago because he was angry at his former common-law wife has pleaded guilty to manslaughter.

Dakota Kashtin Cappo was initially charged with first-degree murder in connection with the fire, which killed a man he didn't know.

A jury trial was set to begin Tuesday and last for three weeks. Before the trial began, Cappo met with his defence lawyer and agreed to plead guilty to the lesser charge of manslaughter.

In an agreed statement of facts, Cappo admitted he was high on methamphetamine on the morning of Nov. 29, 2015, when he started the fire in the apartment complex where his former common-law wife lived with their two children.

The fire spread quickly throughout the building in the Queen Mary Park neighbourhood. Thirty-one people were evacuated from the building.

During a door-to-door check, firefighters found Gregory Fenton unconscious inside Suite No. 303. He was taken to the Royal Alexandra Hospital, where he suffered a cardiac arrest.

Fenton, 54, never regained consciousness and died on Dec. 4, 2015.

Crown prosecutor Terry Hofmann said the medical examiner's office found Fenton suffered no "acute internal injuries."

He said Fenton died from smoke inhalation.

Pattern of harassment

According to the agreed statement of facts, Cappo was involved in six-year relationship with a woman, and they had two children together.

The woman said she ended the relationship in 2013 and restricted access to the children because Cappo was abusing crystal methamphetamine.

Cappo moved to Saskatchewan, but returned to Edmonton in August 2015.

Soon after, he began to threaten the woman on Facebook. He threw rocks and a wrench through her apartment windows and the slashed the tires on her car.

The woman lodged three complaints with Edmonton police near the end of October. She was granted an emergency protection order on Oct. 31.

The harassment and threats continued throughout November.

On Nov. 27, at 2:52 a.m., Cappo made another post on his Facebook page. "I love the way fire burns," he wrote. "And it takes everything away. Plus the smell of smoke remains (sic) me of how the job is done right."

Cappo snuck into the 21-suite apartment building where his former common-law wife lived in the early hours of Nov. 29.

He used an accelerant to start a fire in the south stairwell.

Up to 50 firefighters and Edmonton police responded. The fire caused about $2.5 million in damage.

Dakota Kashtin Cappo initially faced a first-degree murder charge. (Facebook)

Cappo was arrested in September 2016 and charged with first-degree murder and arson.

He is expected back in court on Dec. 7 when a date for his sentencing hearing will be set.