Authorities in southeastern Idaho say an elderly man shot his wife before turning the handgun on himself in what they're calling an apparent murder-suicide.

Robert Butler, an 81-year-old retired Idaho State University professor, and his 78-year-old wife, Tessa Butler, were found dead in their Pocatello home on Wednesday.

Pocatello Police Capt. Rick Capell says evidence collected in the home indicates that Robert Butler shot his wife and then took his own life.

Bannock County Coroner Kim Quick says the couple had a lot of physical problems and "this was a mercy killing."

A longtime friend of the couple, Pocatello resident Priscilla Hearst, says Robert Butler suffered bone loss and could barely walk. Tessa Butler had rheumatoid arthritis and spinal meningitis.