RCMP say Gerald Peters is well known to police, as was his partner Deborah Joseph, who was also 48 and killed in a home on the Tk'emlups First Nations reserve.
Mounties say police and the B.C. Ambulance Service responded to a 911 call on Saturday night.
Police found the woman dead at the home and have not said how she died.
Cpl. Dan Moskaluk says a forensic autopsy was being conducted Monday.
Peters remains in custody.