They arrived separately in Canada about 10 years ago as emigrants from China, and started dating about four years ago.
Now, the man, Jiang Chunqi, stands accused of the second-degree murder of Liu Guanghua.
Recently estranged from Ms. Liu, police say Mr. Jiang was on their radar from the start of their inquires.
"He became a person of interest, or suspect, early on in the investigation," Peel Regional Police Inspector George Koekkoek said Monday at a news conference, where he announced the arrest and charge in what police are calling a "domestic-related homicide."
It was a crime that shook residents of the Greater Toronto Area, when two hands, a foot and a head were discovered in Mississauga's Hewick Meadows Park. Days later, more human remains were found in Scarborough's West Highland Creek. About a week after the first of the grisly discoveries were made, it was revealed the remains belonged to Ms. Liu.
Mr. Jiang was arrested on Sunday in Toronto, Insp. Koekoek said. He did not specify when Mr. Jiang and Ms. Liu ended their relationship.
Police described Mr. Jiang as a Canadian construction worker of Chinese descent who arrived in Canada in 2002. He appeared in court in Brampton on Monday, and was remanded into police custody.
On Monday afternoon, police tape surrounded a unit registered to Mr. Jiang at a Scarborough housing complex. Property records show that Mr. Jiang bought the house last year.
Salma Abdullah, who lives in the unit next to Mr. Jiang, said she would see him in his backyard.
Ms. Abdullah said the neighbourhood is mostly quiet.
"You live here, you feel alone," she said.
Terence Jones, a long-time area resident, said he received a call last week from a police officer who wanted to know about the building's garbage pickup. Mr. Jones said residents leave their trash at designated spots in the building's garage. The police wanted to know who picked up the garbage from the garage but did not say that their questions were linked to the homicide. Police said they could not confirm any link.
A number of aspects in the case are still being investigated, police said, including where and how Ms. Liu was killed. Police said some of her remains still have not been found.
The 41-year-old mother of three was last seen alive in Scarborough when a friend dropped her off at her spa on Aug. 10 around 6:30 p.m. She was later reported missing to Toronto police.
Ms. Liu became the owner of the Forget-Me-Not Health Care spa in May, and she was a licensed holistic practitioner. However, neighbours in the plaza where the spa was located said they saw little business there. Some of the neighbours complained to the city about concerns that it was a front for illegal activities.
Ms. Liu lived in a townhouse in Scarborough near Huntingwood Drive and Kennedy Road.
She arrived in Canada on Feb. 10, 2002, according to court documents on the status of her refugee claim. When she originally landed in Vancouver, she filed for refugee status, and moved to Toronto soon after.
In her refugee claim, Ms. Liu said she feared prosecution in China because she had violated the country's strict birth control policies after she had two sons with her second husband. She had one son from her first marriage.
While she had her third son in secret and left him in the care of relatives, Ms. Liu said the child was eventually discovered by China's family planning officials. She feared she would be sterilized, and she fled to Canada.
The documents also say she owned a barber shop in Changle in Fujian province in the mid-1990s. She also worked in a warehouse.
Police have previously said Ms. Liu's adult son lived with her, while her two younger children lived with their father.
With reports from Amanda Kwan, Celia Donnelly and Rick Cash