Guo spoke little English, had almost no knowledge of the area and knew no one there except her son, a resident on a student visa since 2006.
Two weeks later, with no break in the case, Tang Yuanxi, 25, stood beside his father at a press conference in the Richmond marshlands. That was where Guo had gone for her fateful walk in June, according to her only child.
Carry a large placard with Guo's photo and a police hotline number, the slightly built and bookish young man, said: "I have no idea what happened to my mum. The worst thing is that we are still waiting."
But police are now saying that the young man knew very well what had happened to his mother: He had killed her, stuffed her body into a suitcase and thrown her into the nearby Fraser River.
Tang was arrested last Friday, hours before police revealed that Guo's badly decomposed body had been recovered on a remote island about 200 kilometres northwest of Richmond.
He has been charged with first-degree murder and counselling someone to commit an indictable offence. Police say Tang was plotting to have his grieving father murdered as well.
Sergeant Jennifer Pound of the Royal Canadian Mounted Police said the corpse had apparently been carried by ocean currents until it was found by a beachcomber on uninhabited Harwood Island on July 29.
The discovery had been kept secret by police until Tang's arrest so that it would not imperil the investigation.
Pound, the spokeswoman for the force's integrated homicide investigation team, said: "We had to protect the integrity of this investigation. Should we have gone out with these details, it would have prevented us from utilising a lot of the abilities that we had to bring this [case] to a successful resolution."
Tang, a student at Vancouver's Sprott Shaw Degree College, was scheduled to appear in court yesterday.
Pound said police had the difficult task of informing Tang Jihui in Foshan that his missing wife's body had been found, that their son had been arrested for the killing, and that Tang had been plotting to have him killed as well. Police did not say whether Tang Jihui had been targeted during his six weeks in Canada or afterwards back in China.
Pound said: "As you can well imagine, he's attempting to process all this information. He's going to have a long road of healing ahead of him."
The cause of Guo's death and the motive for the killing have not been revealed. Police also did not say who Tang had allegedly tried to get to kill his father.
The mysterious disappearance of the middle-aged Chinese tourist, with no history of mental illness or unpredictable behaviour, had intrigued Vancouver for two months.
Police with tracker dogs scoured the grassy trails around Richmond where Guo had been fond of walking. About 100 police officers were involved in the search and investigation, as well as officers in China.
Tang helped plaster Richmond with fliers seeking information on his mother's whereabouts, but police now say that was all part of an elaborate bluff.
At the marshlands press conference in June, Tang was asked about rumours that his mother might have decided to start a new life in Canada without him and his father.
Shaking his head, he had responded: "Some have said that my mama would want to stay here. I don't believe that. It's really impossible."
Guo left behind nearly all of her belongings, including her passport and other identification. The only thing missing was her umbrella.
Tang had said then: "I trust the police and now I'm still waiting for my mama."
This article appeared in the South China Morning Post print edition as: Help find my mum, he urged; now son on murder charge
