The ex-husband of a Vancouver mother-of-two shot dead on Valentine's Day has now been charged with her murder.

"Andy" Long Phi Nguyen, 31, was arrested Tuesday night after 30-year-old Jenny Le Wong was found dead in a basement suite in the 3400-block of East Georgia Street. Nguyen was detained by family members at the scene.

"Family members who were in another part of the house at the time of the shooting heard the shots being fired, rushed down and in the chaos managed to disarm the suspect… then hold him for police as we raced there to intervene," Const. Lindsey Houghton said.

Nguyen, who is known to police for drug-related offences, has now been charged with first-degree murder as well as one count of attempted murder. Police say a man described only as "an adult acquaintance of the victim" was also the target of a shot, but suffered just minor wounds from being grazed by a bullet.

The accused man is the father of Wong's children, a five-year-old girl and three-year-old boy. Both youngsters were inside the suite at the time of the shooting, but did not witness it.

"This is a tragic incident that will leave lasting scars, not only on these two children who are now without their mother, but on all the family members," Houghton said.

Investigators are still trying to determine what triggered the tragic violence, and if there is any connection to the romantic holiday.

Nguyen is scheduled to appear in court on Thursday. Wong's death marks the second homicide of 2012 in Vancouver.