Guillaume Gélinas, the man arrested for the first-degree murder of his father and stepmother, is scheduled to be formally charged in a Joliette, Que., courthouse Monday.

The 22-year-old man was arrested in Gatineau in connection with the deaths of Luc Gélinas and Julie Lemieux after police traced his cellphone. He is listed as living in Gatineau on his Facebook profile.

Not much is known about Gélinas, other than that he was in the Canadian Armed Forces reserves and that he spent some time in Afghanistan between 2010 and 2011.

Luc Gélinas wrote on his Facebook page on July 20, 2011 that his son had finally returned from more than eight months in Afghanistan. The above photo of the couple with Guillaume was uploaded to Facebook the same day.

Some people who knew him said he had recently been going through a hard time.

His father and his father’s partner were found dead in their home on Pierre-Le Gardeur Boulevard in Terrebonne, Que., on Thursday. Radio-Canada is reporting that they were stabbed with a sharp object.

The elder Gélinas was 54 years old; Lemieux was 35. Both worked for years at the SAQ, Quebec’s liquor board.

The SAQ issued a formal statement Thursday extending its condolences to the victims’ families and offering support to employees.