It says the RCMP received a request for a wellness check at the residence around 5 p.m. on Friday.
IHIT says in a news release that police responded and found the 71-year-old woman had died.
It says evidence resulted in the arrest of her 38-year-old son, who was also at the scene.
The homicide team has since taken over the investigation but says it is working with Richmond RCMP, the BC Coroners Service and the Integrated Forensic Identification Services on the case.
IHIT Sgt. Timothy Pierotti says in the release that officers believe the incident was isolated and there is no risk to the public, but is asking anyone with information to come forward.
