CHAPEL HILL, N.C. (AP) — Investigators think a man killed his mother before killing himself in their North Carolina home that was listed for sale.

Chapel Hill police told local media outlets Thursday they think 53-year-old Eric Dana Gibson killed 86-year-old Margaret Montgomery Gibson earlier this month.

Police said a real estate agent found the bodies in the master bedroom of the home Oct. 12.

Investigators are awaiting autopsy results to determine how Eric Gibson died.

Police had said there were no visible signs of forced entry into the home.