Family members said the couple did not meet them at a restaurant Friday night. Relatives then called police and asked officers to check on the Millers at their home on Tait Road.
When officers arrived, they said the couple's bodies were found in one of the home's bathrooms, with gunshot wounds.
Police are still trying to determine what led up to the murder-suicide. They are also waiting for some additional toxicology tests from the Montgomery County coroner's office.
Authorities said Richard Miller has been arrested twice for domestic violence when he lived in Oakwood. They said once in December 200 and once before in February 1996 when the alleged victim was his previous wife.