On Sunday, officers responded to a welfare check at a home in the 5600 west block of CR 250 North.
Deputies found three people dead inside the home.
The victims were identified as Harriet Kowalski, 102, Leonard Ciastko, 75, and Linda Ciastko, 73, according to the La Porte County Coroner.
All three victims were found with gunshot wounds to the head, the coroner said.
Mr. Ciastko's daughter called police for a welfare check after she was unable to reach him.
Local officials said there is no threat to the public.