ST. LOUIS (AP) — A St. Louis man has been convicted of killing his ex-girlfriend and her mother and setting a fire that killed his own 10-month-old son. The St. Louis Post-Dispatch reports that 32-year-old Eric Lawson was convicted Saturday in the 2012 killings. The jury will return on Monday to determine if Lawson will receive the death penalty.  Authorities have said Lawson entered the apartment of his ex-girlfriend, 22-year-old Breiana Ray, in May 2012 and shot her and her mother, 50-year-old Gwendolyn Ray. Investigators say he then set two fires in the apartment and locked the door as he exited, trapping his son, Aiden.