The Benton County coroner says 56-year-old Ruth Mertz killed her 28-year-old son, Jason Mertz, at his apartment Friday in Kennewick and then turned the gun on herself.
KVEW reports he died at the scene and she died at a hospital.
The coroner says she left a note that indicated she was responsible for the deaths.
Her husband, Dave Mertz, told KNDU their son had a form of autism that made it difficult for him to socialize. He says she had trouble coming to grips with it and was troubled by their son's unhappiness.