Toronto police are describing the murder of Tess Richey, who was strangled to death in the Gay Village in November, as a crime of opportunity.

On Monday, the force announced that Kalen Schlatter, 21, has been charged with second-degree murder in the death of the 22-year-old woman.

"The opportunity presented itself," said Det-Sgt. Graham Gibson of the crime.

Richey went missing on Nov. 25, 2017, after a night out with a high school friend at Crews and Tangos, a nightclub on Church Street.

Tess Richey is seen in this undated photo provided by her sister, Rachel. (Rachel Richey)

Her body was found at the bottom of an outdoor stairwell at 582 Church St. by her mother and a family friend on Nov. 29, 2017. She was found just doors away from where she was last seen.

​Her cause of death was determined to be neck compression, or strangulation, and the death was ruled a homicide.

At a news conference on Monday, Gibson said Schlatter, who worked as an outdoor contractor, was arrested near his residence in west end Toronto at about 11 p.m. on Sunday night.

Det.-Sgt. Graham Gibson told reporters police arrested Kalen Schlatter late Sunday near his home in Toronto's west end in connection with Tess Richey's murder. 0:40

​Suspect captured on security video

Schlatter and Richey met the night she went missing and spent some time together, said Gibson, who also said police became aware of Schlatter early in the police investigation.

Police found security images of Richey and her friend Ryley Simard walking with a man they believe is Schlatter following the women's exit from the club on Nov. 25 at about 1:30 a.m.

The images show a young man wearing khaki pants and a dark coat. At the time of their release, police described the man as a person of interest in the case.

Security camera images of the man last seen with Richey before she disappeared. (Toronto Police Service)

By 3:45 a.m., after the three stopped to talk to two strangers, one of whom described Richey as seeming "really upset," Simard took the College streetcar home.

One of those strangers, a woman named Michelle whose last name CBC has agreed to withhold, said after seeing a photo from Facebook of Kalen Schlatten on Monday that she believes he was the person she had seen with Richey and Simard.

Other security video shows Richey and the man in an alley near the stairwell. The man was filmed leaving the alley on his own."This is where we last see Tess," Gibson had said.

Chance for family to grieve

Richey's sister Varina was on social media Monday morning announcing the arrest.

"This is not a celebration for us but it is a victory of sorts and we would now like to finally focus our energy and attention on honouring and remembering the best and zaniest little sister any of us Richey girls ever could have asked for," she wrote.

Richey's mother, Christine Hermeston, had come to Toronto from North Bay after Richey's disappearance and discovered her body in the stairwell of a house under renovation on the afternoon of Nov. 29.

She told CBC Toronto last month that she would not go back to North Bay until she found out what happened to her daughter.

Hermeston also posted on Facebook on Monday, writing that "we got him."

Tess Richey's mother, Christine Hermeston, told CBC that searching for the man her daughter was with before she died was like 'living in a nightmare.' (Sue Goodspeed/CBC)

"Such a sad destruction of so many [lives,]" she wrote. "I'm so sad this story ever had to exist but we've far to go."

Richey's family had been critical of how police handled the investigation in its early days, and in December, Toronto police launched a probe into how officers dealt with her disappearance.

On Monday, however, Varina Richey wrote that the family had felt "happy with the progress of the investigation" recently, noting that police had hinted that an arrest was coming for several weeks.

"The family's on very good terms with the members of my team," said Gibson at the news conference. "I speak to Tess's mother probably twice a week."