First came the videos.

Leland Pearl of Saskatoon got one, which was sent from a fake email address. It showed an unknown man slapping Pearl's ex-girlfriend, Alexa Emerson, who was bound at the wrists. The man said Emerson's "blood would be on his hands" if Pearl did not give up custody of his son.

Then came the bomb threats and the ominous packages. Over a six-month period, 17 businesses, schools and hospitals throughout Saskatoon received bomb threats and/or packages containing a mysterious white powder said to be anthrax.

And then police and local media outlets received another strange video, in which a mystery woman claimed responsibility for the white powder. It led Saskatoon Crime Stoppers on a massive hunt to find the woman billed as "the greatest Where's Waldo internet challenge ever."

Court in Saskatoon this week heard one woman was behind it all — Emerson herself. Court heard that she created fake accounts, hired actors and fabricated dramatic scenes to threaten her ex-boyfriends.

The Alexa Emerson Story 1:38

This week she pleaded guilty to 15 charges, including public mischief, uttering death threats and criminal harassment. They represent a condensed version of her original 81 charges.

Emerson, 33, was sentenced to two years less a day, and a three-year probation order that includes a psychiatric treatment.

In all, nine people received strange online messages containing threats and harassment. The city of Saskatoon spent about $200,000 responding to emergencies. At least 25 people were exposed to the white powder, which in some cases turned out to be baking soda.

'Obvious obsessive nature'

A 10-page agreed statement of facts presented at Court of Queen's Bench on Wednesday lays out in detail how Emerson's actions affected people, businesses, schools and hospitals in Saskatoon.

It's a complicated document.

Emerson's sentence includes psychiatric treatment. (Saskatoon Police Service)

Emerson used social media to disrupt lives and the community, the document reveals. For all the complexity of her methods, Crown prosecutor Jennifer Claxton-Viczko says Emerson's motives were not terrifically complicated. They spoke to a woman with significant mental health issues, the prosecutor says.

"I think anybody looking at the circumstances of the offences, the obvious obsessive nature of harassing ex-boyfriend after ex-boyfriend after ex-boyfriend, would leave even the common person with the belief that she needed some psychiatric assistance," Claxton-Viczko said after sentencing.

A gathering storm

Alexa Emerson's circle of victims started small, according to the statement of facts.

Between September and December 2016, she directly targeted Leland Pearl with Facebook messages and emails that were described in the court document as "vulgar and threatening."

To do so, she created fake email accounts using the names of people in his wider circle.

This involved Celynne Braun, Pearl's ex-wife. Emerson also dragged an ex-boyfriend of Braun's into the mix by attributing the messages to him.

She also targeted Jeri-Lynn Johnston, Pearl's sister, and Johnston's workplace, Airline Hotels in downtown Saskatoon, with disturbing messages, including the graphic videos. The Shark Club, a bar and grill, also received one.

"The videos caused great alarm for Leland Pearl and his family, as well as Savanna Drilling staff [and] the Shark Club staff, who at the time employed Emerson, and James Avery, a former boyfriend to Emerson," the statement of facts said.

On Nov. 29, 2016, Emerson's tactics escalated.

'In this letter is anthrax … Merry Christmas'

Police and emergency services responded to five calls about suspicious packages in one hour that day.

The first came from Cut Casual Steak House on 21st Street E. Someone had hand-delivered an envelope to the restaurant over the lunch hour.

A staff member opened it and discovered white powder and a note.

"In this letter is Anthrax, try not to inhale, Merry Christmas," it read.

The cost of emergency responders related to incidents involving Emerson was more than $200,000. Police and emergency services responded to five calls about suspicious packages in one hour on one day. (CBC)

Within the hour, similar packages arrived at the Ernst & Young office and the Airline Hotels main office, both downtown, and the Sandman Hotel/Shark Club and Country Inns and Suites in the city's north end.

All the packages were signed "Celynne Braun" — the name of Pearl's ex-wife.

Police, fire and paramedics converged on the scenes. The hazmat trailer and a command centre closed off much of the downtown. Anyone who came into contact with the powder had to be decontaminated.

In the end, the powder turned out to be harmless.

"The five businesses targeted on November 29, 2016 can all be linked to Alexa Emerson," the statement of facts read.

Emerson worked at Cut Steak House. The Shark Club was her previous employer. Ernst & Young is where a previous boyfriend worked. Airline Hotels is where Pearl's sister Jeri-Lynn Johnston worked. Country Inn and Suites is where Johnston's husband worked.

Winter of white powder scares

It was a long winter for Saskatoon police and emergency services.

Between November 2016 and April 2017 nine individuals were targeted with emails, threats and harassment by Emerson, who used various aliases.

Seventeen businesses, schools and hospitals received bomb threats and/or packages with the mysterious white powder. At least 25 people came into direct contact with the powder and had to live with the fear they had been poisoned.

The city estimated it cost more than $200,000 to deal with the emergency calls.

American actress Samantha Field was hired to impersonate a victim's cousin in a video message claiming responsibility for the white powder attacks. She's seen in a still from the video on the left, and in an interview with CBC on the right. (CBC)

In April 2017, police and local media outlets received a bizarre video featuring a young woman claiming to be Jade Braun. In the video, the woman claimed responsibility for distributing the white powder packages.

The real Jayde Braun is Celynne Braun's cousin.

It turned out that Emerson had hired an American actress named Samantha Field to read the script on camera. Field, who was hired for the job through a website, believed the recording was for a book reading.

A day of reckoning

Eight of Emerson's targets submitted victim impact statements at her plea and sentencing this week.

The victims described, as Celynne Braun put it, what it was like to be "under constant attack by a complete stranger."

Leland Pearl said the experience "stripped away my confidence. I don't trust people now."

An officer on 21st Street at the first white powder call on Nov. 29, 2016. Emerson was sentenced to two years less a day, plus three years of probation. She will spend another 115 days behind bars before her release. (CBC)

Steve Johnston, Jeri-Lynn Johnston's husband, described Emerson's actions as "a rampage of social media terrorism."

Justice Gerald Allbright accepted the joint sentencing submission by Claxton-Viczko and defence lawyer Patrick McDougall.

He imposed a sentence of two years less a day, plus three years of probation.

Given that Emerson had been in custody since April 2017, that means she was given another 115 days behind bars before her release.

As part of the probation, Allbright ordered that she take any psychiatric treatment recommended by her probation officer.

And he offered a hard caution.

"Assume that somebody is watching what you do," he said.

Alexa Emerson declined to speak in court.