Jeremy Gubbels, 26, appeared in a Sarnia court via video on Wednesday and was remanded in custody.
He is charged with two counts of first degree murder in connection with the deaths of his parents, 55-year-old Susan Gubbels and 54-year-old Mario Gubbels of Warwick Township.
Susan's body was found at the couple's home on Arkona Road, northeast of Watford, around 9 p.m. on Sunday, and that of her husband was found in a vehicle in the area of Richmond Street and Queens Avenue in London around 10:45 p.m.
Jeremy was arrested by London police around 11 p.m. at a restaurant near where the vehicle was located.
No details of what was discussed in court Wednesday can be released.
He is scheduled to appear in court again on July 29.
Family speaks
Pat Gubbels and his wife Shirley - Mario's brother and sister-in-law - say the family, which includes eight siblings, is still reeling from the news.
"We just sat here all day and talked and tried to make sense out of it and support each other and just be around each other," Pat says.
Shirley describes the moment they heard the news, "They just told me, but we only knew about Mario at that time, and then it was about an hour or so later she phoned back and said they'd found Sue too."
Pat and Shirley lost their son in a car crash last September and say Mario and Susan were there to offer support - and share the troubles they were having with their son.
"[Mario] says, 'Pat, I know you lost your son. I've lost my son, but he's still alive and I'm fighting to get him back.'"
They say their nephew suffers from a mental illness, but despite his run-ins with the law and even trashing his parents' home, Mario and Susan still supported him.
"[They were] always there for Jeremy," Shirley says. "Even through his illness they were always stood behind that boy, they never gave up."
Just last week all the families got together and Shirley says Sue asked her to take a picture of Jeremy with his sister Amanda so she would have a more recent photo.
Funeral arrangements for the couple will be made once autopsies have been completed.