Police said they believe Margaret Montgomery Gibson, 86, was killed by her son, Eric Dana Gibson, 58.
Police said Eric Gibson's cause of death is still pending autopsy and toxicology results.
Police said earlier there were no visible signs of forced entry into the home.
The case remains under investigation.
The bodies were discovered on October 12 by a Realtor.
READ MORE: Realtor finds 2 bodies inside Chapel Hill home