Muskogee, Okla., police tell PEOPLE Johnson's mother-in-law Terry Janway was found dead in her home along with her husband Jack and their grandson Dalton Sean Neumann is a reporter at PEOPLE.

Terry Janway, 68, and Jack Janway, 69, were the parents of Johnson's wife, Chandra. Dalton Janway, 11, was the son of one of Chandra's siblings. The incident occurred in Muskogee, Oklahoma.

late Monday night. Local police said Terry Janway, 68, was found dead inside the home along with Jack Janway, 69, and their 11-year-old grandson Dalton Janway. Police told PEOPLE they suspect ...